4.4.21-stable review

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Michael Neuling <[email protected]>

commit 190ce8693c23eae09ba5f303a83bf2fbeb6478b1 upstream.

Currently we have 2 segments that are bolted for the kernel linear mapping (ie 0xc000... addresses). This is 0 to 1TB and also the kernel stacks. Anything accessed outside of these regions may need to be faulted in. (In practice machines with TM always have 1T segments)

If a machine has < 2TB of memory we never fault on the kernel linear mapping as these two segments cover all physical memory. If a machine has > 2TB of memory, there may be structures outside of these two segments that need to be faulted in. This faulting can occur when running as a guest as the hypervisor may remove any SLB that's not bolted.

When we treclaim and trecheckpoint we have a window where we need to run with the userspace GPRs. This means that we no longer have a valid stack pointer in r1. For this window we therefore clear MSR RI to indicate that any exceptions taken at this point won't be able to be handled. This means that we can't take segment misses in this RI=0 window.

In this RI=0 region, we currently access the thread_struct for the process being context switched to or from. This thread_struct access may cause a segment fault since it's not guaranteed to be covered by the two bolted segment entries described above.

We've seen this with a crash when running as a guest with > 2TB of memory on PowerVM:

Unrecoverable exception 4100 at c00000000004f138

  Oops: Unrecoverable exception, sig: 6 [#1]
  SMP NR_CPUS=2048 NUMA pSeries
  CPU: 1280 PID: 7755 Comm: kworker/1280:1 Tainted: G                 X 4.4.13-46-default #1
  task: c000189001df4210 ti: c000189001d5c000 task.ti: c000189001d5c000
  NIP: c00000000004f138 LR: 0000000010003a24 CTR: 0000000010001b20
  REGS: c000189001d5f730 TRAP: 4100   Tainted: G                 X  (4.4.13-46-default)
  MSR: 8000000100001031 <SF,ME,IR,DR,LE>  CR: 24000048  XER: 00000000
  CFAR: c00000000004ed18 SOFTE: 0
  GPR00: ffffffffc58d7b60 c000189001d5f9b0 00000000100d7d00 000000003a738288
  GPR04: 0000000000002781 0000000000000006 0000000000000000 c0000d1f4d889620
  GPR08: 000000000000c350 00000000000008ab 00000000000008ab 00000000100d7af0
  GPR12: 00000000100d7ae8 00003ffe787e67a0 0000000000000000 0000000000000211
  GPR16: 0000000010001b20 0000000000000000 0000000000800000 00003ffe787df110
  GPR20: 0000000000000001 00000000100d1e10 0000000000000000 00003ffe787df050
  GPR24: 0000000000000003 0000000000010000 0000000000000000 00003fffe79e2e30
  GPR28: 00003fffe79e2e68 00000000003d0f00 00003ffe787e67a0 00003ffe787de680
  NIP [c00000000004f138] restore_gprs+0xd0/0x16c
  LR [0000000010003a24] 0x10003a24
  Call Trace:
  [c000189001d5f9b0] [c000189001d5f9f0] 0xc000189001d5f9f0 (unreliable)
  [c000189001d5fb90] [c00000000001583c] tm_recheckpoint+0x6c/0xa0
  [c000189001d5fbd0] [c000000000015c40] __switch_to+0x2c0/0x350
  [c000189001d5fc30] [c0000000007e647c] __schedule+0x32c/0x9c0
  [c000189001d5fcb0] [c0000000007e6b58] schedule+0x48/0xc0
  [c000189001d5fce0] [c0000000000deabc] worker_thread+0x22c/0x5b0
  [c000189001d5fd80] [c0000000000e7000] kthread+0x110/0x130
  [c000189001d5fe30] [c000000000009538] ret_from_kernel_thread+0x5c/0xa4
  Instruction dump:
  7cb103a6 7cc0e3a6 7ca222a6 78a58402 38c00800 7cc62838 08860000 7cc000a6
  38a00006 78c60022 7cc62838 0b060000 <e8c701a0> 7ccff120 e8270078 e8a70098
  ---[ end trace 602126d0a1dedd54 ]---

This fixes this by copying the required data from the thread_struct to the stack before we clear MSR RI. Then once we clear RI, we only access the stack, guaranteeing there's no segment miss.

We also tighten the region over which we set RI=0 on the treclaim() path. This may have a slight performance impact since we're adding an mtmsr instruction.

---
 arch/powerpc/kernel/tm.S |   61 +++++++++++++++++++++++++++++++++--------------
 1 file changed, 44 insertions(+), 17 deletions(-)

@@ -110,17 +110,11 @@ _GLOBAL(tm_reclaim)
 	std	r3, STK_PARAM(R3)(r1)
 	SAVE_NVGPRS(r1)
 
-	/* We need to setup MSR for VSX register save instructions.  Here we
-	 * also clear the MSR RI since when we do the treclaim, we won't have a
-	 * valid kernel pointer for a while.  We clear RI here as it avoids
-	 * adding another mtmsr closer to the treclaim.  This makes the region
-	 * maked as non-recoverable wider than it needs to be but it saves on
-	 * inserting another mtmsrd later.
-	 */
+	/* We need to setup MSR for VSX register save instructions. */
 	mfmsr	r14
 	mr	r15, r14
 	ori	r15, r15, MSR_FP
-	li	r16, MSR_RI
+	li	r16, 0
 	ori	r16, r16, MSR_EE /* IRQs hard off */
 	andc	r15, r15, r16
 	oris	r15, r15, MSR_VEC@h

@@ -176,7 +170,17 @@ dont_backup_fp:
 1:	tdeqi   r6, 0
 	EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0
 
-	/* The moment we treclaim, ALL of our GPRs will switch
+	/* Clear MSR RI since we are about to change r1, EE is already off. */
+	li	r4, 0
+	mtmsrd	r4, 1
+
+	/*
+	 * BE CAREFUL HERE:
+	 * At this point we can't take an SLB miss since we have MSR_RI
+	 * off. Load only to/from the stack/paca which are in SLB bolted regions
+	 * until we turn MSR RI back on.
+	 *
+	 * The moment we treclaim, ALL of our GPRs will switch
 	 * to user register state.  (FPRs, CCR etc. also!)
 	 * Use an sprg and a tm_scratch in the PACA to shuffle.
 	 */

@@ -197,6 +201,11 @@ dont_backup_fp:
 
 	/* Store the PPR in r11 and reset to decent value */
 	std	r11, GPR11(r1)			/* Temporary stash */
+
+	/* Reset MSR RI so we can take SLB faults again */
+	li	r11, MSR_RI
+	mtmsrd	r11, 1
+
 	mfspr	r11, SPRN_PPR
 	HMT_MEDIUM
 

@@ -397,11 +406,6 @@ restore_gprs:
 	ld	r5, THREAD_TM_DSCR(r3)
 	ld	r6, THREAD_TM_PPR(r3)
 
-	/* Clear the MSR RI since we are about to change R1.  EE is already off
-	 */
-	li	r4, 0
-	mtmsrd	r4, 1
-
 	REST_GPR(0, r7)				/* GPR0 */
 	REST_2GPRS(2, r7)			/* GPR2-3 */
 	REST_GPR(4, r7)				/* GPR4 */

@@ -439,10 +443,33 @@ restore_gprs:
 	ld	r6, _CCR(r7)
 	mtcr    r6
 
-	REST_GPR(1, r7)				/* GPR1 */
-	REST_GPR(5, r7)				/* GPR5-7 */
 	REST_GPR(6, r7)
-	ld	r7, GPR7(r7)
+
+	/*
+	 * Store r1 and r5 on the stack so that we can access them
+	 * after we clear MSR RI.
+	 */
+
+	REST_GPR(5, r7)
+	std	r5, -8(r1)
+	ld	r5, GPR1(r7)
+	std	r5, -16(r1)
+
+	REST_GPR(7, r7)
+
+	/* Clear MSR RI since we are about to change r1. EE is already off */
+	li	r5, 0
+	mtmsrd	r5, 1
+
+	/*
+	 * BE CAREFUL HERE:
+	 * At this point we can't take an SLB miss since we have MSR_RI
+	 * off. Load only to/from the stack/paca which are in SLB bolted regions
+	 * until we turn MSR RI back on.
+	 */
+
+	ld	r5, -8(r1)
+	ld	r1, -16(r1)
 
 	/* Commit register state as checkpointed state: */
 	TRECHKPT

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Kangjie Lu <[email protected]>

commit 4116def2337991b39919f3b448326e21c40e0dbb upstream.

The last field "flags" of object "minfo" is not initialized. Copying this object out may leak kernel stack data. Assign 0 to it to avoid leak.

---
 net/rds/recv.c |    2 ++
 1 file changed, 2 insertions(+)

@@ -545,5 +545,7 @@ void rds_inc_info_copy(struct rds_incomi
 		minfo.fport = inc->i_hdr.h_dport;
 	}
 
+	minfo.flags = 0;
+
 	rds_info_copy(iter, &minfo, sizeof(minfo));
 }

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Martin Schwidefsky <[email protected]>

commit 532c34b5fbf1687df63b3fcd5b2846312ac943c6 upstream.

The sclp_ctl_ioctl_sccb function uses two copy_from_user calls to retrieve the sclp request from user space. The first copy_from_user fetches the length of the request which is stored in the first two bytes of the request. The second copy_from_user gets the complete sclp request, but this copies the length field a second time. A malicious user may have changed the length in the meantime.

---
 drivers/s390/char/sclp_ctl.c |   12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

@@ -56,6 +56,7 @@ static int sclp_ctl_ioctl_sccb(void __us
 {
 	struct sclp_ctl_sccb ctl_sccb;
 	struct sccb_header *sccb;
+	unsigned long copied;
 	int rc;
 
 	if (copy_from_user(&ctl_sccb, user_area, sizeof(ctl_sccb)))

@@ -65,14 +66,15 @@ static int sclp_ctl_ioctl_sccb(void __us
 	sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
 	if (!sccb)
 		return -ENOMEM;
-	if (copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), sizeof(*sccb))) {
+	copied = PAGE_SIZE -
+		copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), PAGE_SIZE);
+	if (offsetof(struct sccb_header, length) +
+	    sizeof(sccb->length) > copied || sccb->length > copied) {
 		rc = -EFAULT;
 		goto out_free;
 	}
-	if (sccb->length > PAGE_SIZE || sccb->length < 8)
-		return -EINVAL;
-	if (copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), sccb->length)) {
-		rc = -EFAULT;
+	if (sccb->length < 8) {
+		rc = -EINVAL;
 		goto out_free;
 	}
 	rc = sclp_sync_request(ctl_sccb.cmdw, sccb);

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Daniel Vetter <[email protected]>

commit 6f00975c619064a18c23fd3aced325ae165a73b9 upstream.

Somehow this one slipped through, which means drivers without modeset support can be oopsed (since those also don't call drm_mode_config_init, which means the crtc lookup will chase an uninitalized idr).

---
 drivers/gpu/drm/drm_crtc.c |    3 +++
 1 file changed, 3 insertions(+)

@@ -5231,6 +5231,9 @@ int drm_mode_page_flip_ioctl(struct drm_
 	unsigned long flags;
 	int ret = -EINVAL;
 
+	if (!drm_core_check_feature(dev, DRIVER_MODESET))
+		return -EINVAL;
+
 	if (page_flip->flags & ~DRM_MODE_PAGE_FLIP_FLAGS ||
 	    page_flip->reserved != 0)
 		return -EINVAL;

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Rob Clark <[email protected]>

commit 89f82cbb0d5c0ab768c8d02914188aa2211cd2e3 upstream.

Use instead __copy_from_user_inatomic() and fallback to slow-path where we drop and re-aquire the lock in case of fault.

---
 drivers/gpu/drm/msm/msm_gem_submit.c |   27 ++++++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

@@ -55,6 +55,14 @@ static struct msm_gem_submit *submit_cre
 	return submit;
 }
 
+static inline unsigned long __must_check
+copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
+{
+	if (access_ok(VERIFY_READ, from, n))
+		return __copy_from_user_inatomic(to, from, n);
+	return -EFAULT;
+}
+
 static int submit_lookup_objects(struct msm_gem_submit *submit,
 		struct drm_msm_gem_submit *args, struct drm_file *file)
 {

@@ -62,6 +70,7 @@ static int submit_lookup_objects(struct
 	int ret = 0;
 
 	spin_lock(&file->table_lock);
+	pagefault_disable();
 
 	for (i = 0; i < args->nr_bos; i++) {
 		struct drm_msm_gem_submit_bo submit_bo;

@@ -70,10 +79,15 @@ static int submit_lookup_objects(struct
 		void __user *userptr =
 			to_user_ptr(args->bos + (i * sizeof(submit_bo)));
 
-		ret = copy_from_user(&submit_bo, userptr, sizeof(submit_bo));
-		if (ret) {
-			ret = -EFAULT;
-			goto out_unlock;
+		ret = copy_from_user_inatomic(&submit_bo, userptr, sizeof(submit_bo));
+		if (unlikely(ret)) {
+			pagefault_enable();
+			spin_unlock(&file->table_lock);
+			ret = copy_from_user(&submit_bo, userptr, sizeof(submit_bo));
+			if (ret)
+				goto out;
+			spin_lock(&file->table_lock);
+			pagefault_disable();
 		}
 
 		if (submit_bo.flags & ~MSM_SUBMIT_BO_FLAGS) {

@@ -113,9 +127,12 @@ static int submit_lookup_objects(struct
 	}
 
 out_unlock:
-	submit->nr_bos = i;
+	pagefault_enable();
 	spin_unlock(&file->table_lock);
 
+out:
+	submit->nr_bos = i;
+
 	return ret;
 }
 

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Christoph Huber <[email protected]>

commit 3e103a65514c2947e53f3171b21255fbde8b60c6 upstream.

commit cbaadf0f90d6 ("ASoC: atmel_ssc_dai: refactor the startup and shutdown") refactored code such that the SSC is reset on every startup; this breaks duplex audio (e.g. first start audio playback, then start record, causing the playback to stop/hang)

---
 sound/soc/atmel/atmel_ssc_dai.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

@@ -298,8 +298,9 @@ static int atmel_ssc_startup(struct snd_
 	clk_enable(ssc_p->ssc->clk);
 	ssc_p->mck_rate = clk_get_rate(ssc_p->ssc->clk);
 
-	/* Reset the SSC to keep it at a clean status */
-	ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
+	/* Reset the SSC unless initialized to keep it in a clean state */
+	if (!ssc_p->initialized)
+		ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
 
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		dir = 0;

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Jake Oshins <[email protected]>

[ Upstream commit e16dad6bfe1437aaee565f875a6713ca7ce81bdf ]

In existing code, this tree of resources is created in single-threaded code and never modified after it is created, and thus needs no locking. This patch introduces a semaphore for tree access, as other patches in this series introduce run-time modifications of this resource tree which can happen on multiple threads.

---
 drivers/hv/vmbus_drv.c |   16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

@@ -105,6 +105,7 @@ static struct notifier_block hyperv_pani
 };
 
 struct resource *hyperv_mmio;
+DEFINE_SEMAPHORE(hyperv_mmio_lock);
 
 static int vmbus_exists(void)
 {

@@ -1140,7 +1141,10 @@ int vmbus_allocate_mmio(struct resource
 	resource_size_t range_min, range_max, start, local_min, local_max;
 	const char *dev_n = dev_name(&device_obj->device);
 	u32 fb_end = screen_info.lfb_base + (screen_info.lfb_size << 1);
-	int i;
+	int i, retval;
+
+	retval = -ENXIO;
+	down(&hyperv_mmio_lock);
 
 	for (iter = hyperv_mmio; iter; iter = iter->sibling) {
 		if ((iter->start >= max) || (iter->end <= min))

@@ -1177,13 +1181,17 @@ int vmbus_allocate_mmio(struct resource
 			for (; start + size - 1 <= local_max; start += align) {
 				*new = request_mem_region_exclusive(start, size,
 								    dev_n);
-				if (*new)
-					return 0;
+				if (*new) {
+					retval = 0;
+					goto exit;
+				}
 			}
 		}
 	}
 
-	return -ENXIO;
+exit:
+	up(&hyperv_mmio_lock);
+	return retval;
 }
 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
 

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Dave Chinner <[email protected]>

commit f3d7ebdeb2c297bd26272384e955033493ca291c upstream.

verifier and triggered only for the primary superblock via a "bp->b_bn == XFS_SB_DADDR" check.

Unfortunately, the primary superblock is an uncached buffer, and hence it is configured by xfs_buf_read_uncached() with:

	bp->b_bn = XFS_BUF_DADDR_NULL;  /* always null for uncached buffers */

And so this check never triggers. Fix it.

---
 fs/xfs/libxfs/xfs_sb.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -581,7 +581,8 @@ xfs_sb_verify(
 	 * Only check the in progress field for the primary superblock as
 	 * mkfs.xfs doesn't clear it from secondary superblocks.
 	 */
-	return xfs_mount_validate_sb(mp, &sb, bp->b_bn == XFS_SB_DADDR,
+	return xfs_mount_validate_sb(mp, &sb,
+				     bp->b_maps[0].bm_bn == XFS_SB_DADDR,
 				     check_version);
 }
 

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: John Stultz <[email protected]>

commit a4f8f6667f099036c88f231dcad4cf233652c824 upstream.

It was reported that hibernation could fail on the 2nd attempt, where the system hangs at hibernate() -> syscore_resume() -> i8237A_resume() -> claim_dma_lock(), because the lock has already been taken.

However there is actually no other process would like to grab this lock on that problematic platform.

Further investigation showed that the problem is triggered by setting /sys/power/pm_trace to 1 before the 1st hibernation.

Since once pm_trace is enabled, the rtc becomes unmeaningful after suspend, and meanwhile some BIOSes would like to adjust the 'invalid' RTC (e.g, smaller than 1970) to the release date of that motherboard during POST stage, thus after resumed, it may seem that the system had a significant long sleep time which is a completely meaningless value.

Then in timekeeping_resume -> tk_debug_account_sleep_time, if the bit31 of the sleep time happened to be set to 1, fls() returns 32 and we add 1 to sleep_time_bin[32], which causes an out of bounds array access and therefor memory being overwritten.

As depicted by System.map:
0xffffffff81c9d080 b sleep_time_bin 0xffffffff81c9d100 B dma_spin_lock
the dma_spin_lock.val is set to 1, which caused this problem.

This patch adds a sanity check in tk_debug_account_sleep_time() to ensure we don't index past the sleep_time_bin array.

[jstultz: Problem diagnosed and original patch by Chen Yu, I've solved the
issue slightly differently, but borrowed his excelent explanation of the issue here.]

---
 kernel/time/timekeeping_debug.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

@@ -23,7 +23,9 @@
 
 #include "timekeeping_internal.h"
 
-static unsigned int sleep_time_bin[32] = {0};
+#define NUM_BINS 32
+
+static unsigned int sleep_time_bin[NUM_BINS] = {0};
 
 static int tk_debug_show_sleep_time(struct seq_file *s, void *data)
 {

@@ -69,6 +71,9 @@ late_initcall(tk_debug_sleep_time_init);
 
 void tk_debug_account_sleep_time(struct timespec64 *t)
 {
-	sleep_time_bin[fls(t->tv_sec)]++;
+	/* Cap bin index so we don't overflow the array */
+	int bin = min(fls(t->tv_sec), NUM_BINS-1);
+
+	sleep_time_bin[bin]++;
 }
 

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: John Stultz <[email protected]>

commit 27727df240c7cc84f2ba6047c6f18d5addfd25ef upstream.

When I added some extra sanity checking in timekeeping_get_ns() under CONFIG_DEBUG_TIMEKEEPING, I missed that the NMI safe __ktime_get_fast_ns() method was using timekeeping_get_ns().

Thus the locking added to the debug checks broke the NMI-safety of __ktime_get_fast_ns().

This patch open-codes the timekeeping_get_ns() logic for __ktime_get_fast_ns(), so can avoid any deadlocks in NMI.

---
 kernel/time/timekeeping.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

@@ -383,7 +383,10 @@ static __always_inline u64 __ktime_get_f
 	do {
 		seq = raw_read_seqcount_latch(&tkf->seq);
 		tkr = tkf->base + (seq & 0x01);
-		now = ktime_to_ns(tkr->base) + timekeeping_get_ns(tkr);
+		now = ktime_to_ns(tkr->base);
+
+		now += clocksource_delta(tkr->read(tkr->clock),
+					 tkr->cycle_last, tkr->mask);
 	} while (read_seqcount_retry(&tkf->seq, seq));
 
 	return now;

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Al Viro <[email protected]>

commit 57b8f112cfe6622ddddb8c2641206bb5fa8a112d upstream.

---
 drivers/staging/lustre/lustre/llite/llite_internal.h |    2 --
 1 file changed, 2 deletions(-)

@@ -631,8 +631,6 @@ struct ll_file_data {
 
 struct lov_stripe_md;
 
-extern spinlock_t inode_lock;
-
 extern struct dentry *llite_root;
 extern struct kset *llite_kset;
 

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Al Viro <[email protected]>

commit 5955102c9984fa081b2d570cfac75c97eecf8f3b upstream

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared.

---
 include/linux/fs.h |   29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

@@ -710,6 +710,31 @@ enum inode_i_mutex_lock_class
 	I_MUTEX_PARENT2,
 };
 
+static inline void inode_lock(struct inode *inode)
+{
+	mutex_lock(&inode->i_mutex);
+}
+
+static inline void inode_unlock(struct inode *inode)
+{
+	mutex_unlock(&inode->i_mutex);
+}
+
+static inline int inode_trylock(struct inode *inode)
+{
+	return mutex_trylock(&inode->i_mutex);
+}
+
+static inline int inode_is_locked(struct inode *inode)
+{
+	return mutex_is_locked(&inode->i_mutex);
+}
+
+static inline void inode_lock_nested(struct inode *inode, unsigned subclass)
+{
+	mutex_lock_nested(&inode->i_mutex, subclass);
+}
+
 void lock_two_nondirectories(struct inode *, struct inode*);
 void unlock_two_nondirectories(struct inode *, struct inode*);
 

@@ -3029,8 +3054,8 @@ static inline bool dir_emit_dots(struct
 }
 static inline bool dir_relax(struct inode *inode)
 {
-	mutex_unlock(&inode->i_mutex);
-	mutex_lock(&inode->i_mutex);
+	inode_unlock(inode);
+	inode_lock(inode);
 	return !IS_DEADDIR(inode);
 }
 

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Miklos Szeredi <[email protected]>

commit 0956254a2d5b9e2141385514553aeef694dfe3b5 upstream.

When a copy up of a directory occurs which has the opaque xattr set, the xattr remains in the upper directory. The immediate behavior with overlayfs is that the upper directory is not treated as opaque, however after a remount the opaque flag is used and upper directory is treated as opaque. This causes files created in the lower layer to be hidden when using multiple lower directories.

Fix by not copying up the opaque flag.

To reproduce:

----8<---------8<---------8<---------8<---------8<---------8<----
mkdir -p l/d/s u v w mnt
mount -t overlay overlay -olowerdir=l,upperdir=u,workdir=w mnt rm -rf mnt/d/
mkdir -p mnt/d/n
umount mnt
mount -t overlay overlay -olowerdir=u:l,upperdir=v,workdir=w mnt touch mnt/d/foo
umount mnt
mount -t overlay overlay -olowerdir=u:l,upperdir=v,workdir=w mnt ls mnt/d
----8<---------8<---------8<---------8<---------8<---------8<----

output should be: "foo n"

---
 fs/overlayfs/copy_up.c   |    2 ++
 fs/overlayfs/inode.c     |    2 +-
 fs/overlayfs/overlayfs.h |    1 +
 3 files changed, 4 insertions(+), 1 deletion(-)

@@ -48,6 +48,8 @@ int ovl_copy_xattr(struct dentry *old, s
 	}
 
 	for (name = buf; name < (buf + list_size); name += strlen(name) + 1) {
+		if (ovl_is_private_xattr(name))
+			continue;
 retry:
 		size = vfs_getxattr(old, name, value, value_size);
 		if (size == -ERANGE)

@@ -219,7 +219,7 @@ static int ovl_readlink(struct dentry *d
 }
 
 
-static bool ovl_is_private_xattr(const char *name)
+bool ovl_is_private_xattr(const char *name)
 {
 	return strncmp(name, OVL_XATTR_PRE_NAME, OVL_XATTR_PRE_LEN) == 0;
 }

@@ -174,6 +174,7 @@ ssize_t ovl_getxattr(struct dentry *dent
 ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
 int ovl_removexattr(struct dentry *dentry, const char *name);
 struct inode *ovl_d_select_inode(struct dentry *dentry, unsigned file_flags);
+bool ovl_is_private_xattr(const char *name);
 
 struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
 			    struct ovl_entry *oe);

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Miklos Szeredi <[email protected]>

commit c11b9fdd6a612f376a5e886505f1c54c16d8c380 upstream.

Clear out posix acl xattrs on workdir and also reset the mode after creation so that an inherited sgid bit is cleared.

---
 fs/overlayfs/super.c |   19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

@@ -763,6 +763,10 @@ retry:
 		struct kstat stat = {
 			.mode = S_IFDIR | 0,
 		};
+		struct iattr attr = {
+			.ia_valid = ATTR_MODE,
+			.ia_mode = stat.mode,
+		};
 
 		if (work->d_inode) {
 			err = -EEXIST;

@@ -778,6 +782,21 @@ retry:
 		err = ovl_create_real(dir, work, &stat, NULL, NULL, true);
 		if (err)
 			goto out_dput;
+
+		err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_DEFAULT);
+		if (err && err != -ENODATA)
+			goto out_dput;
+
+		err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_ACCESS);
+		if (err && err != -ENODATA)
+			goto out_dput;
+
+		/* Clear any inherited mode bits */
+		inode_lock(work->d_inode);
+		err = notify_change(work, &attr, NULL);
+		inode_unlock(work->d_inode);
+		if (err)
+			goto out_dput;
 	}
 out_unlock:
 	mutex_unlock(&dir->i_mutex);

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Miklos Szeredi <[email protected]>

commit 7cb35119d067191ce9ebc380a599db0b03cbd9d9 upstream.

Be defensive about what underlying fs provides us in the returned xattr list buffer. If it's not properly null terminated, bail out with a warning insead of BUG.

---
 fs/overlayfs/inode.c |   17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

@@ -277,7 +277,8 @@ ssize_t ovl_listxattr(struct dentry *den
 	struct path realpath;
 	enum ovl_path_type type = ovl_path_real(dentry, &realpath);
 	ssize_t res;
-	int off;
+	size_t len;
+	char *s;
 
 	res = vfs_listxattr(realpath.dentry, list, size);
 	if (res <= 0 || size == 0)

@@ -287,17 +288,19 @@ ssize_t ovl_listxattr(struct dentry *den
 		return res;
 
 	/* filter out private xattrs */
-	for (off = 0; off < res;) {
-		char *s = list + off;
-		size_t slen = strlen(s) + 1;
+	for (s = list, len = res; len;) {
+		size_t slen = strnlen(s, len) + 1;
 
-		BUG_ON(off + slen > res);
+		/* underlying fs providing us with an broken xattr list? */
+		if (WARN_ON(slen > len))
+			return -EIO;
 
+		len -= slen;
 		if (ovl_is_private_xattr(s)) {
 			res -= slen;
-			memmove(s, s + slen, res - off);
+			memmove(s, s + slen, len);
 		} else {
-			off += slen;
+			s += slen;
 		}
 	}
 

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Miklos Szeredi <[email protected]>

commit e1ff3dd1ae52cef5b5373c8cc4ad949c2c25a71c upstream.

Workdir creation fails in latest kernel.

Fix by allowing EOPNOTSUPP as a valid return value from vfs_removexattr(XATTR_NAME_POSIX_ACL_*). Upper filesystem may not support ACL and still be perfectly able to support overlayfs.

---
 fs/overlayfs/super.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

@@ -784,11 +784,11 @@ retry:
 			goto out_dput;
 
 		err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_DEFAULT);
-		if (err && err != -ENODATA)
+		if (err && err != -ENODATA && err != -EOPNOTSUPP)
 			goto out_dput;
 
 		err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_ACCESS);
-		if (err && err != -ENODATA)
+		if (err && err != -ENODATA && err != -EOPNOTSUPP)
 			goto out_dput;
 
 		/* Clear any inherited mode bits */

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Kent Overstreet <[email protected]>

commit acc9cf8c66c66b2cbbdb4a375537edee72be64df upstream.

This patch fixes a cachedev registration-time allocation deadlock. This can deadlock on boot if your initrd auto-registeres bcache devices:

Allocator thread:

[  720.727614] INFO: task bcache_allocato:3833 blocked for more than 120 seconds.
[  720.732361]  [<ffffffff816eeac7>] schedule+0x37/0x90
[  720.732963]  [<ffffffffa05192b8>] bch_bucket_alloc+0x188/0x360 [bcache]
[  720.733538]  [<ffffffff810e6950>] ? prepare_to_wait_event+0xf0/0xf0
[  720.734137]  [<ffffffffa05302bd>] bch_prio_write+0x19d/0x340 [bcache]
[  720.734715]  [<ffffffffa05190bf>] bch_allocator_thread+0x3ff/0x470 [bcache]
[  720.735311]  [<ffffffff816ee41c>] ? __schedule+0x2dc/0x950
[  720.735884]  [<ffffffffa0518cc0>] ? invalidate_buckets+0x980/0x980 [bcache]

Registration thread:

[  720.710403] INFO: task bash:3531 blocked for more than 120 seconds.
[  720.715226]  [<ffffffff816eeac7>] schedule+0x37/0x90
[  720.715805]  [<ffffffffa05235cd>] __bch_btree_map_nodes+0x12d/0x150 [bcache]
[  720.716409]  [<ffffffffa0522d30>] ? bch_btree_insert_check_key+0x1c0/0x1c0 [bcache]
[  720.717008]  [<ffffffffa05236e4>] bch_btree_insert+0xf4/0x170 [bcache]
[  720.717586]  [<ffffffff810e6950>] ? prepare_to_wait_event+0xf0/0xf0
[  720.718191]  [<ffffffffa0527d9a>] bch_journal_replay+0x14a/0x290 [bcache]
[  720.718766]  [<ffffffff810cc90d>] ? ttwu_do_activate.constprop.94+0x5d/0x70
[  720.719369]  [<ffffffff810cf684>] ? try_to_wake_up+0x1d4/0x350
[  720.719968]  [<ffffffffa05317d0>] run_cache_set+0x580/0x8e0 [bcache]
[  720.720553]  [<ffffffffa053302e>] register_bcache+0xe2e/0x13b0 [bcache]
[  720.721153]  [<ffffffff81354cef>] kobj_attr_store+0xf/0x20
[  720.721730]  [<ffffffff812a2dad>] sysfs_kf_write+0x3d/0x50
[  720.722327]  [<ffffffff812a225a>] kernfs_fop_write+0x12a/0x180
[  720.722904]  [<ffffffff81225177>] __vfs_write+0x37/0x110
[  720.723503]  [<ffffffff81228048>] ? __sb_start_write+0x58/0x110
[  720.724100]  [<ffffffff812cedb3>] ? security_file_permission+0x23/0xa0
[  720.724675]  [<ffffffff812258a9>] vfs_write+0xa9/0x1b0
[  720.725275]  [<ffffffff8102479c>] ? do_audit_syscall_entry+0x6c/0x70
[  720.725849]  [<ffffffff81226755>] SyS_write+0x55/0xd0
[  720.726451]  [<ffffffff8106a390>] ? do_page_fault+0x30/0x80
[  720.727045]  [<ffffffff816f2cae>] system_call_fastpath+0x12/0x71

The fifo code in upstream bcache can't use the last element in the buffer, which was the cause of the bug: if you asked for a power of two size, it'd give you a fifo that could hold one less than what you asked for rather than allocating a buffer twice as big.

---
 drivers/md/bcache/super.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -1818,7 +1818,7 @@ static int cache_alloc(struct cache_sb *
 	free = roundup_pow_of_two(ca->sb.nbuckets) >> 10;
 
 	if (!init_fifo(&ca->free[RESERVE_BTREE], 8, GFP_KERNEL) ||
-	    !init_fifo(&ca->free[RESERVE_PRIO], prio_buckets(ca), GFP_KERNEL) ||
+	    !init_fifo_exact(&ca->free[RESERVE_PRIO], prio_buckets(ca), GFP_KERNEL) ||
 	    !init_fifo(&ca->free[RESERVE_MOVINGGC], free, GFP_KERNEL) ||
 	    !init_fifo(&ca->free[RESERVE_NONE], free, GFP_KERNEL) ||
 	    !init_fifo(&ca->free_inc,	free << 2, GFP_KERNEL) ||

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Benjamin Coddington <[email protected]>

commit a77ec83a57890240c546df00ca5df1cdeedb1cc3 upstream.

The address of the iovec &vq->iov[out] is not guaranteed to contain the scsi command's response iovec throughout the lifetime of the command. Rather, it is more likely to contain an iovec from an immediately following command after looping back around to vhost_get_vq_desc(). Pass along the iovec entirely instead.

---
 drivers/vhost/scsi.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

@@ -88,7 +88,7 @@ struct vhost_scsi_cmd {
 	struct scatterlist *tvc_prot_sgl;
 	struct page **tvc_upages;
 	/* Pointer to response header iovec */
-	struct iovec *tvc_resp_iov;
+	struct iovec tvc_resp_iov;
 	/* Pointer to vhost_scsi for our device */
 	struct vhost_scsi *tvc_vhost;
 	/* Pointer to vhost_virtqueue for the cmd */

@@ -557,7 +557,7 @@ static void vhost_scsi_complete_cmd_work
 		memcpy(v_rsp.sense, cmd->tvc_sense_buf,
 		       se_cmd->scsi_sense_length);
 
-		iov_iter_init(&iov_iter, READ, cmd->tvc_resp_iov,
+		iov_iter_init(&iov_iter, READ, &cmd->tvc_resp_iov,
 			      cmd->tvc_in_iovs, sizeof(v_rsp));
 		ret = copy_to_iter(&v_rsp, sizeof(v_rsp), &iov_iter);
 		if (likely(ret == sizeof(v_rsp))) {

@@ -1054,7 +1054,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *
 		}
 		cmd->tvc_vhost = vs;
 		cmd->tvc_vq = vq;
-		cmd->tvc_resp_iov = &vq->iov[out];
+		cmd->tvc_resp_iov = vq->iov[out];
 		cmd->tvc_in_iovs = in;
 
 		pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n",

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Wanpeng Li <[email protected]>

commit 2e63ad4bd5dd583871e6602f9d398b9322d358d9 upstream.

native_smp_prepare_cpus
-> default_setup_apic_routing

    -> enable_IR_x2apic
      -> irq_remapping_prepare
        -> intel_prepare_irq_remapping
          -> intel_setup_irq_remapping

So IR table is setup even if "noapic" boot parameter is added. As a result we crash later when the interrupt affinity is set due to a half initialized remapping infrastructure.

Prevent remap initialization when IOAPIC is disabled.

---
 arch/x86/kernel/apic/apic.c |    3 +++
 1 file changed, 3 insertions(+)

@@ -1587,6 +1587,9 @@ void __init enable_IR_x2apic(void)
 	unsigned long flags;
 	int ret, ir_stat;
 
+	if (skip_ioapic_setup)
+		return;
+
 	ir_stat = irq_remapping_prepare();
 	if (ir_stat < 0 && !x2apic_supported())
 		return;

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Oleg Nesterov <[email protected]>

commit 6c4687cc17a788a6dd8de3e27dbeabb7cbd3e066 upstream.

__replace_page() wronlgy calls mem_cgroup_cancel_charge() in "success" path, it should only do this if page_check_address() fails.

This means that every enable/disable leads to unbalanced mem_cgroup_uncharge() from put_page(old_page), it is trivial to underflow the page_counter->count and trigger OOM.

---
 kernel/events/uprobes.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

@@ -171,8 +171,10 @@ static int __replace_page(struct vm_area
 	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
 	err = -EAGAIN;
 	ptep = page_check_address(page, mm, addr, &ptl, 0);
-	if (!ptep)
+	if (!ptep) {
+		mem_cgroup_cancel_charge(kpage, memcg);
 		goto unlock;
+	}
 
 	get_page(kpage);
 	page_add_new_anon_rmap(kpage, vma, addr);

@@ -199,7 +201,6 @@ static int __replace_page(struct vm_area
 
 	err = 0;
  unlock:
-	mem_cgroup_cancel_charge(kpage, memcg);
 	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
 	unlock_page(page);
 	return err;

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Ken Lin <[email protected]>

commit 83d9956b7e6b310c1062df7894257251c625b22e upstream.

Avoid getting sample rate on B850V3 CP2114 as it is unsupported and causes noisy "current rate is different from the runtime rate" messages when playback starts.

---
 sound/usb/quirks.c |    1 +
 1 file changed, 1 insertion(+)

@@ -1142,6 +1142,7 @@ bool snd_usb_get_sample_rate_quirk(struc
 	case USB_ID(0x0556, 0x0014): /* Phoenix Audio TMX320VC */
 	case USB_ID(0x05A3, 0x9420): /* ELP HD USB Camera */
 	case USB_ID(0x074D, 0x3553): /* Outlaw RR2150 (Micronas UAC3553B) */
+	case USB_ID(0x1901, 0x0191): /* GE B850V3 CP2114 audio interface */
 	case USB_ID(0x1de7, 0x0013): /* Phoenix Audio MT202exe */
 	case USB_ID(0x1de7, 0x0014): /* Phoenix Audio TMX320 */
 	case USB_ID(0x1de7, 0x0114): /* Phoenix Audio MT202pcs */

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Takashi Sakamoto <[email protected]>

commit 04b2d9c9c319277ad4fbbb71855c256a9f4d5f98 upstream.

In hwdep interface of firewire-tascam driver, accessing to user space is in a critical section with disabled local interrupt. Depending on architecture, accessing to user space can cause page fault exception. Then local processor stores machine status and handle the synchronous event. A handler corresponding to the event can call task scheduler to wait for preparing pages. In a case of usage of single core processor, the state to disable local interrupt is worse because it doesn't handle usual interrupts from hardware.

This commit fixes this bug, by performing the accessing outside spinlock.

---
 sound/firewire/tascam/tascam-hwdep.c |   33 +++++++++++----------------------
 1 file changed, 11 insertions(+), 22 deletions(-)

@@ -16,31 +16,14 @@
 
 #include "tascam.h"
 
-static long hwdep_read_locked(struct snd_tscm *tscm, char __user *buf,
-			      long count)
-{
-	union snd_firewire_event event;
-
-	memset(&event, 0, sizeof(event));
-
-	event.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS;
-	event.lock_status.status = (tscm->dev_lock_count > 0);
-	tscm->dev_lock_changed = false;
-
-	count = min_t(long, count, sizeof(event.lock_status));
-
-	if (copy_to_user(buf, &event, count))
-		return -EFAULT;
-
-	return count;
-}
-
 static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
 		       loff_t *offset)
 {
 	struct snd_tscm *tscm = hwdep->private_data;
 	DEFINE_WAIT(wait);
-	union snd_firewire_event event;
+	union snd_firewire_event event = {
+		.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS,
+	};
 
 	spin_lock_irq(&tscm->lock);
 

@@ -54,10 +37,16 @@ static long hwdep_read(struct snd_hwdep
 		spin_lock_irq(&tscm->lock);
 	}
 
-	memset(&event, 0, sizeof(event));
-	count = hwdep_read_locked(tscm, buf, count);
+	event.lock_status.status = (tscm->dev_lock_count > 0);
+	tscm->dev_lock_changed = false;
+
 	spin_unlock_irq(&tscm->lock);
 
+	count = min_t(long, count, sizeof(event.lock_status));
+
+	if (copy_to_user(buf, &event, count))
+		return -EFAULT;
+
 	return count;
 }
 

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Takashi Sakamoto <[email protected]>

commit 6b1ca4bcadf9ef077cc5f03c6822ba276ed14902 upstream.

In hwdep interface of fireworks driver, accessing to user space is in a critical section with disabled local interrupt. Depending on architecture, accessing to user space can cause page fault exception. Then local processor stores machine status and handles the synchronous event. A handler corresponding to the event can call task scheduler to wait for preparing pages. In a case of usage of single core processor, the state to disable local interrupt is worse because it don't handle usual interrupts from hardware.

This commit fixes this bug, performing the accessing outside spinlock. This commit also gives up counting the number of queued response messages to simplify ring-buffer management.

---
 sound/firewire/fireworks/fireworks.h             |    1 
 sound/firewire/fireworks/fireworks_hwdep.c       |   71 ++++++++++++++++-------
 sound/firewire/fireworks/fireworks_proc.c        |    4 -
 sound/firewire/fireworks/fireworks_transaction.c |    5 -
 4 files changed, 56 insertions(+), 25 deletions(-)

@@ -106,7 +106,6 @@ struct snd_efw {
 	u8 *resp_buf;
 	u8 *pull_ptr;
 	u8 *push_ptr;
-	unsigned int resp_queues;
 };
 
 int snd_efw_transaction_cmd(struct fw_unit *unit,

@@ -188,8 +188,8 @@ proc_read_queues_state(struct snd_info_e
 	else
 		consumed = (unsigned int)(efw->push_ptr - efw->pull_ptr);
 
-	snd_iprintf(buffer, "%d %d/%d\n",
-		    efw->resp_queues, consumed, snd_efw_resp_buf_size);
+	snd_iprintf(buffer, "%d/%d\n",
+		    consumed, snd_efw_resp_buf_size);
 }
 
 static void

@@ -121,11 +121,11 @@ copy_resp_to_buf(struct snd_efw *efw, vo
 	size_t capacity, till_end;
 	struct snd_efw_transaction *t;
 
-	spin_lock_irq(&efw->lock);
-
 	t = (struct snd_efw_transaction *)data;
 	length = min_t(size_t, be32_to_cpu(t->length) * sizeof(u32), length);
 
+	spin_lock_irq(&efw->lock);
+
 	if (efw->push_ptr < efw->pull_ptr)
 		capacity = (unsigned int)(efw->pull_ptr - efw->push_ptr);
 	else

@@ -155,7 +155,6 @@ copy_resp_to_buf(struct snd_efw *efw, vo
 	}
 
 	/* for hwdep */
-	efw->resp_queues++;
 	wake_up(&efw->hwdep_wait);
 
 	*rcode = RCODE_COMPLETE;

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Takashi Iwai <[email protected]>

commit 816f318b2364262a51024096da7ca3b84e78e3b5 upstream.

When a seq-virmidi driver is initialized, it registers a rawmidi instance with its callback to create an associated seq kernel client. Currently it's done throughly in rawmidi's register_mutex context. Recently it was found that this may lead to a deadlock another rawmidi device that is being attached with the sequencer is accessed, as both open with the same register_mutex. This was actually triggered by syzkaller, as Dmitry Vyukov reported:

======================================================
[ INFO: possible circular locking dependency detected ]
4.8.0-rc1+ #11 Not tainted
-------------------------------------------------------
syz-executor/7154 is trying to acquire lock:
(register_mutex#5){+.+.+.}, at: [<ffffffff84fd6d4b>] snd_rawmidi_kernel_open+0x4b/0x260 sound/core/rawmidi.c:341

but task is already holding lock:
(&grp->list_mutex){++++.+}, at: [<ffffffff850138bb>] check_and_subscribe_port+0x5b/0x5c0 sound/core/seq/seq_ports.c:495

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&grp->list_mutex){++++.+}:

    [<ffffffff8147a3a8>] lock_acquire+0x208/0x430 kernel/locking/lockdep.c:3746
    [<ffffffff863f6199>] down_read+0x49/0xc0 kernel/locking/rwsem.c:22
    [<     inline     >] deliver_to_subscribers sound/core/seq/seq_clientmgr.c:681
    [<ffffffff85005c5e>] snd_seq_deliver_event+0x35e/0x890 sound/core/seq/seq_clientmgr.c:822
    [<ffffffff85006e96>] > snd_seq_kernel_client_dispatch+0x126/0x170 sound/core/seq/seq_clientmgr.c:2418
    [<ffffffff85012c52>] snd_seq_system_broadcast+0xb2/0xf0 sound/core/seq/seq_system.c:101
    [<ffffffff84fff70a>] snd_seq_create_kernel_client+0x24a/0x330 sound/core/seq/seq_clientmgr.c:2297
    [<     inline     >] snd_virmidi_dev_attach_seq sound/core/seq/seq_virmidi.c:383
    [<ffffffff8502d29f>] snd_virmidi_dev_register+0x29f/0x750 sound/core/seq/seq_virmidi.c:450
    [<ffffffff84fd208c>] snd_rawmidi_dev_register+0x30c/0xd40 sound/core/rawmidi.c:1645
    [<ffffffff84f816d3>] __snd_device_register.part.0+0x63/0xc0 sound/core/device.c:164
    [<     inline     >] __snd_device_register sound/core/device.c:162
    [<ffffffff84f8235d>] snd_device_register_all+0xad/0x110 sound/core/device.c:212
    [<ffffffff84f7546f>] snd_card_register+0xef/0x6c0 sound/core/init.c:749
    [<ffffffff85040b7f>] snd_virmidi_probe+0x3ef/0x590 sound/drivers/virmidi.c:123
    [<ffffffff833ebf7b>] platform_drv_probe+0x8b/0x170 drivers/base/platform.c:564
    ......

-> #0 (register_mutex#5){+.+.+.}:

    [<     inline     >] check_prev_add kernel/locking/lockdep.c:1829
    [<     inline     >] check_prevs_add kernel/locking/lockdep.c:1939
    [<     inline     >] validate_chain kernel/locking/lockdep.c:2266
    [<ffffffff814791f4>] __lock_acquire+0x4d44/0x4d80 kernel/locking/lockdep.c:3335
    [<ffffffff8147a3a8>] lock_acquire+0x208/0x430 kernel/locking/lockdep.c:3746
    [<     inline     >] __mutex_lock_common kernel/locking/mutex.c:521
    [<ffffffff863f0ef1>] mutex_lock_nested+0xb1/0xa20 kernel/locking/mutex.c:621
    [<ffffffff84fd6d4b>] snd_rawmidi_kernel_open+0x4b/0x260 sound/core/rawmidi.c:341
    [<ffffffff8502e7c7>] midisynth_subscribe+0xf7/0x350 sound/core/seq/seq_midi.c:188
    [<     inline     >] subscribe_port sound/core/seq/seq_ports.c:427
    [<ffffffff85013cc7>] check_and_subscribe_port+0x467/0x5c0 sound/core/seq/seq_ports.c:510
    [<ffffffff85015da9>] snd_seq_port_connect+0x2c9/0x500 sound/core/seq/seq_ports.c:579
    [<ffffffff850079b8>] snd_seq_ioctl_subscribe_port+0x1d8/0x2b0 sound/core/seq/seq_clientmgr.c:1480
    [<ffffffff84ffe9e4>] snd_seq_do_ioctl+0x184/0x1e0 sound/core/seq/seq_clientmgr.c:2225
    [<ffffffff84ffeae8>] snd_seq_kernel_client_ctl+0xa8/0x110 sound/core/seq/seq_clientmgr.c:2440
    [<ffffffff85027664>] snd_seq_oss_midi_open+0x3b4/0x610 sound/core/seq/oss/seq_oss_midi.c:375
    [<ffffffff85023d67>] snd_seq_oss_synth_setup_midi+0x107/0x4c0 sound/core/seq/oss/seq_oss_synth.c:281
    [<ffffffff8501b0a8>] snd_seq_oss_open+0x748/0x8d0 sound/core/seq/oss/seq_oss_init.c:274
    [<ffffffff85019d8a>] odev_open+0x6a/0x90 sound/core/seq/oss/seq_oss.c:138
    [<ffffffff84f7040f>] soundcore_open+0x30f/0x640 sound/sound_core.c:639
    ......

other info that might help us debug this:

 Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&grp->list_mutex);
                                lock(register_mutex#5);
                                lock(&grp->list_mutex);

lock(register_mutex#5);

*** DEADLOCK ***
======================================================

The fix is to simply move the registration parts in snd_rawmidi_dev_register() to the outside of the register_mutex lock. The lock is needed only to manage the linked list, and it's not necessarily to cover the whole initialization process.

---
 sound/core/rawmidi.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

@@ -1633,11 +1633,13 @@ static int snd_rawmidi_dev_register(stru
 		return -EBUSY;
 	}
 	list_add_tail(&rmidi->list, &snd_rawmidi_devices);
+	mutex_unlock(&register_mutex);
 	err = snd_register_device(SNDRV_DEVICE_TYPE_RAWMIDI,
 				  rmidi->card, rmidi->device,
 				  &snd_rawmidi_f_ops, rmidi, &rmidi->dev);
 	if (err < 0) {
 		rmidi_err(rmidi, "unable to register\n");
+		mutex_lock(&register_mutex);
 		list_del(&rmidi->list);
 		mutex_unlock(&register_mutex);
 		return err;

@@ -1645,6 +1647,7 @@ static int snd_rawmidi_dev_register(stru
 	if (rmidi->ops && rmidi->ops->dev_register &&
 	    (err = rmidi->ops->dev_register(rmidi)) < 0) {
 		snd_unregister_device(&rmidi->dev);
+		mutex_lock(&register_mutex);
 		list_del(&rmidi->list);
 		mutex_unlock(&register_mutex);
 		return err;

@@ -1677,7 +1680,6 @@ static int snd_rawmidi_dev_register(stru
 		}
 	}
 #endif /* CONFIG_SND_OSSEMUL */
-	mutex_unlock(&register_mutex);
 	sprintf(name, "midi%d", rmidi->device);
 	entry = snd_info_create_card_entry(rmidi->card, name, rmidi->card->proc_root);
 	if (entry) {

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Shrirang Bagul <[email protected]>

commit 311042d1b67d9a1856a8e1294e7729fb86f64014 upstream.

This patch enables headset microphone on some variants of Dell Inspiron 5468. (Dell SSID 0x07ad)

---
 sound/pci/hda/patch_realtek.c |    4 ++++
 1 file changed, 4 insertions(+)

@@ -5879,6 +5879,10 @@ static const struct snd_hda_pin_quirk al
 		{0x12, 0x90a60170},
 		{0x14, 0x90170120},
 		{0x21, 0x02211030}),
+	SND_HDA_PIN_QUIRK(0x10ec0256, 0x1028, "Dell Inspiron 5468", ALC255_FIXUP_DELL1_MIC_NO_PRESENCE,
+		{0x12, 0x90a60180},
+		{0x14, 0x90170120},
+		{0x21, 0x02211030}),
 	SND_HDA_PIN_QUIRK(0x10ec0256, 0x1028, "Dell", ALC255_FIXUP_DELL1_MIC_NO_PRESENCE,
 		ALC256_STANDARD_PINS),
 	SND_HDA_PIN_QUIRK(0x10ec0280, 0x103c, "HP", ALC280_FIXUP_HP_GPIO4,

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: David Howells <[email protected]>

[ Upstream commit 23c8a812dc3c621009e4f0e5342aa4e2ede1ceaa ]

This fixes CVE-2016-0758.

In the ASN.1 decoder, when the length field of an ASN.1 value is extracted, it isn't validated against the remaining amount of data before being added to the cursor. With a sufficiently large size indicated, the check:

datalen - dp < 2

may then fail due to integer overflow.

Fix this by checking the length indicated against the amount of remaining data in both places a definite length is determined.

Whilst we're at it, make the following changes:

(1) Check the maximum size of extended length does not exceed the capacity of the variable it's being stored in (len) rather than the type that variable is assumed to be (size_t).

(2) Compare the EOC tag to the symbolic constant ASN1_EOC rather than the integer 0.

(3) To reduce confusion, move the initialisation of len outside of:

	for (len = 0; n > 0; n--) {

     since it doesn't have anything to do with the loop counter n.

---
 lib/asn1_decoder.c |   16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

@@ -74,7 +74,7 @@ next_tag:
 
 	/* Extract a tag from the data */
 	tag = data[dp++];
-	if (tag == 0) {
+	if (tag == ASN1_EOC) {
 		/* It appears to be an EOC. */
 		if (data[dp++] != 0)
 			goto invalid_eoc;

@@ -96,10 +96,8 @@ next_tag:
 
 	/* Extract the length */
 	len = data[dp++];
-	if (len <= 0x7f) {
-		dp += len;
-		goto next_tag;
-	}
+	if (len <= 0x7f)
+		goto check_length;
 
 	if (unlikely(len == ASN1_INDEFINITE_LENGTH)) {
 		/* Indefinite length */

@@ -110,14 +108,18 @@ next_tag:
 	}
 
 	n = len - 0x80;
-	if (unlikely(n > sizeof(size_t) - 1))
+	if (unlikely(n > sizeof(len) - 1))
 		goto length_too_long;
 	if (unlikely(n > datalen - dp))
 		goto data_overrun_error;
-	for (len = 0; n > 0; n--) {
+	len = 0;
+	for (; n > 0; n--) {
 		len <<= 8;
 		len |= data[dp++];
 	}
+check_length:
+	if (len > datalen - dp)
+		goto data_overrun_error;
 	dp += len;
 	goto next_tag;
 

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Kai-Heng Feng <[email protected]>

commit fd06c77eb9200b53d421da5fffe0dcd894b5d72a upstream.

The subwoofer on Inspiron 7559 was disabled originally. Applying a pin fixup to node 0x1b can enable it and make it work.

Old pin: 0x411111f0
New pin: 0x90170151

---
 sound/pci/hda/patch_realtek.c |   11 +++++++++++
 1 file changed, 11 insertions(+)

@@ -4840,6 +4840,7 @@ enum {
 	ALC221_FIXUP_HP_FRONT_MIC,
 	ALC292_FIXUP_TPT460,
 	ALC298_FIXUP_SPK_VOLUME,
+	ALC256_FIXUP_DELL_INSPIRON_7559_SUBWOOFER,
 };
 
 static const struct hda_fixup alc269_fixups[] = {

@@ -5501,6 +5502,15 @@ static const struct hda_fixup alc269_fix
 		.chained = true,
 		.chain_id = ALC298_FIXUP_DELL1_MIC_NO_PRESENCE,
 	},
+	[ALC256_FIXUP_DELL_INSPIRON_7559_SUBWOOFER] = {
+		.type = HDA_FIXUP_PINS,
+		.v.pins = (const struct hda_pintbl[]) {
+			{ 0x1b, 0x90170151 },
+			{ }
+		},
+		.chained = true,
+		.chain_id = ALC255_FIXUP_DELL1_MIC_NO_PRESENCE
+	},
 };
 
 static const struct snd_pci_quirk alc269_fixup_tbl[] = {

@@ -5545,6 +5555,7 @@ static const struct snd_pci_quirk alc269
 	SND_PCI_QUIRK(0x1028, 0x06df, "Dell", ALC293_FIXUP_DISABLE_AAMIX_MULTIJACK),
 	SND_PCI_QUIRK(0x1028, 0x06e0, "Dell", ALC293_FIXUP_DISABLE_AAMIX_MULTIJACK),
 	SND_PCI_QUIRK(0x1028, 0x0704, "Dell XPS 13 9350", ALC256_FIXUP_DELL_XPS_13_HEADPHONE_NOISE),
+	SND_PCI_QUIRK(0x1028, 0x0706, "Dell Inspiron 7559", ALC256_FIXUP_DELL_INSPIRON_7559_SUBWOOFER),
 	SND_PCI_QUIRK(0x1028, 0x0725, "Dell Inspiron 3162", ALC255_FIXUP_DELL_SPK_NOISE),
 	SND_PCI_QUIRK(0x1028, 0x075b, "Dell XPS 13 9360", ALC256_FIXUP_DELL_XPS_13_HEADPHONE_NOISE),
 	SND_PCI_QUIRK(0x1028, 0x075d, "Dell AIO", ALC298_FIXUP_SPK_VOLUME),

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Vegard Nossum <[email protected]>

commit 11749e086b2766cccf6217a527ef5c5604ba069c upstream.

I got this with syzkaller:

    ==================================================================
    BUG: KASAN: null-ptr-deref on address 0000000000000020
    Read of size 32 by task syz-executor/22519
    CPU: 1 PID: 22519 Comm: syz-executor Not tainted 4.8.0-rc2+ #169
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2
    014
     0000000000000001 ffff880111a17a00 ffffffff81f9f141 ffff880111a17a90
     ffff880111a17c50 ffff880114584a58 ffff880114584a10 ffff880111a17a80
     ffffffff8161fe3f ffff880100000000 ffff880118d74a48 ffff880118d74a68
    Call Trace:
     [<ffffffff81f9f141>] dump_stack+0x83/0xb2
     [<ffffffff8161fe3f>] kasan_report_error+0x41f/0x4c0
     [<ffffffff8161ff74>] kasan_report+0x34/0x40
     [<ffffffff82c84b54>] ? snd_timer_user_read+0x554/0x790
     [<ffffffff8161e79e>] check_memory_region+0x13e/0x1a0
     [<ffffffff8161e9c1>] kasan_check_read+0x11/0x20
     [<ffffffff82c84b54>] snd_timer_user_read+0x554/0x790
     [<ffffffff82c84600>] ? snd_timer_user_info_compat.isra.5+0x2b0/0x2b0
     [<ffffffff817d0831>] ? proc_fault_inject_write+0x1c1/0x250
     [<ffffffff817d0670>] ? next_tgid+0x2a0/0x2a0
     [<ffffffff8127c278>] ? do_group_exit+0x108/0x330
     [<ffffffff8174653a>] ? fsnotify+0x72a/0xca0
     [<ffffffff81674dfe>] __vfs_read+0x10e/0x550
     [<ffffffff82c84600>] ? snd_timer_user_info_compat.isra.5+0x2b0/0x2b0
     [<ffffffff81674cf0>] ? do_sendfile+0xc50/0xc50
     [<ffffffff81745e10>] ? __fsnotify_update_child_dentry_flags+0x60/0x60
     [<ffffffff8143fec6>] ? kcov_ioctl+0x56/0x190
     [<ffffffff81e5ada2>] ? common_file_perm+0x2e2/0x380
     [<ffffffff81746b0e>] ? __fsnotify_parent+0x5e/0x2b0
     [<ffffffff81d93536>] ? security_file_permission+0x86/0x1e0
     [<ffffffff816728f5>] ? rw_verify_area+0xe5/0x2b0
     [<ffffffff81675355>] vfs_read+0x115/0x330
     [<ffffffff81676371>] SyS_read+0xd1/0x1a0
     [<ffffffff816762a0>] ? vfs_write+0x4b0/0x4b0
     [<ffffffff82001c2c>] ? __this_cpu_preempt_check+0x1c/0x20
     [<ffffffff8150455a>] ? __context_tracking_exit.part.4+0x3a/0x1e0
     [<ffffffff816762a0>] ? vfs_write+0x4b0/0x4b0
     [<ffffffff81005524>] do_syscall_64+0x1c4/0x4e0
     [<ffffffff810052fc>] ? syscall_return_slowpath+0x16c/0x1d0
     [<ffffffff83c3276a>] entry_SYSCALL64_slow_path+0x25/0x25
    ==================================================================

There are a couple of problems that I can see:

- ioctl(SNDRV_TIMER_IOCTL_SELECT), which potentially sets tu->queue/tu->tqueue to NULL on memory allocation failure, so read() would get a NULL pointer dereference like the above splat

- the same ioctl() can free tu->queue/to->tqueue which means read() could potentially see (and dereference) the freed pointer

We can fix both by taking the ioctl_lock mutex when dereferencing ->queue/->tqueue, since that's always held over all the ioctl() code.

Just looking at the code I find it likely that there are more problems here such as tu->qhead pointing outside the buffer if the size is changed concurrently using SNDRV_TIMER_IOCTL_PARAMS.

---
 sound/core/timer.c |    2 ++
 1 file changed, 2 insertions(+)

@@ -1967,6 +1967,7 @@ static ssize_t snd_timer_user_read(struc
 		tu->qused--;
 		spin_unlock_irq(&tu->qlock);
 
+		mutex_lock(&tu->ioctl_lock);
 		if (tu->tread) {
 			if (copy_to_user(buffer, &tu->tqueue[qhead],
 					 sizeof(struct snd_timer_tread)))

@@ -1976,6 +1977,7 @@ static ssize_t snd_timer_user_read(struc
 					 sizeof(struct snd_timer_read)))
 				err = -EFAULT;
 		}
+		mutex_unlock(&tu->ioctl_lock);
 
 		spin_lock_irq(&tu->qlock);
 		if (err < 0)

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Vegard Nossum <[email protected]>

commit 6b760bb2c63a9e322c0e4a0b5daf335ad93d5a33 upstream.

I got this:

    divide error: 0000 [#1] PREEMPT SMP KASAN
    CPU: 1 PID: 1327 Comm: a.out Not tainted 4.8.0-rc2+ #189
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
    task: ffff8801120a9580 task.stack: ffff8801120b0000
    RIP: 0010:[<ffffffff82c8bd9a>]  [<ffffffff82c8bd9a>] snd_hrtimer_callback+0x1da/0x3f0
    RSP: 0018:ffff88011aa87da8  EFLAGS: 00010006
    RAX: 0000000000004f76 RBX: ffff880112655e88 RCX: 0000000000000000
    RDX: 0000000000000000 RSI: ffff880112655ea0 RDI: 0000000000000001
    RBP: ffff88011aa87e00 R08: ffff88013fff905c R09: ffff88013fff9048
    R10: ffff88013fff9050 R11: 00000001050a7b8c R12: ffff880114778a00
    R13: ffff880114778ab4 R14: ffff880114778b30 R15: 0000000000000000
    FS:  00007f071647c700(0000) GS:ffff88011aa80000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000603001 CR3: 0000000112021000 CR4: 00000000000006e0
    Stack:
     0000000000000000 ffff880114778ab8 ffff880112655ea0 0000000000004f76
     ffff880112655ec8 ffff880112655e80 ffff880112655e88 ffff88011aa98fc0
     00000000b97ccf2b dffffc0000000000 ffff88011aa98fc0 ffff88011aa87ef0
    Call Trace:
     <IRQ>
     [<ffffffff813abce7>] __hrtimer_run_queues+0x347/0xa00
     [<ffffffff82c8bbc0>] ? snd_hrtimer_close+0x130/0x130
     [<ffffffff813ab9a0>] ? retrigger_next_event+0x1b0/0x1b0
     [<ffffffff813ae1a6>] ? hrtimer_interrupt+0x136/0x4b0
     [<ffffffff813ae220>] hrtimer_interrupt+0x1b0/0x4b0
     [<ffffffff8120f91e>] local_apic_timer_interrupt+0x6e/0xf0
     [<ffffffff81227ad3>] ? kvm_guest_apic_eoi_write+0x13/0xc0
     [<ffffffff83c35086>] smp_apic_timer_interrupt+0x76/0xa0
     [<ffffffff83c3416c>] apic_timer_interrupt+0x8c/0xa0
     <EOI>
     [<ffffffff83c3239c>] ? _raw_spin_unlock_irqrestore+0x2c/0x60
     [<ffffffff82c8185d>] snd_timer_start1+0xdd/0x670
     [<ffffffff82c87015>] snd_timer_continue+0x45/0x80
     [<ffffffff82c88100>] snd_timer_user_ioctl+0x1030/0x2830
     [<ffffffff8159f3a0>] ? __follow_pte.isra.49+0x430/0x430
     [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80
     [<ffffffff815a26fa>] ? do_wp_page+0x3aa/0x1c90
     [<ffffffff815aa4f8>] ? handle_mm_fault+0xbc8/0x27f0
     [<ffffffff815a9930>] ? __pmd_alloc+0x370/0x370
     [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80
     [<ffffffff816b0733>] do_vfs_ioctl+0x193/0x1050
     [<ffffffff816b05a0>] ? ioctl_preallocate+0x200/0x200
     [<ffffffff81002f2f>] ? syscall_trace_enter+0x3cf/0xdb0
     [<ffffffff815045ba>] ? __context_tracking_exit.part.4+0x9a/0x1e0
     [<ffffffff81002b60>] ? exit_to_usermode_loop+0x190/0x190
     [<ffffffff82001a97>] ? check_preemption_disabled+0x37/0x1e0
     [<ffffffff81d93889>] ? security_file_ioctl+0x89/0xb0
     [<ffffffff816b167f>] SyS_ioctl+0x8f/0xc0
     [<ffffffff816b15f0>] ? do_vfs_ioctl+0x1050/0x1050
     [<ffffffff81005524>] do_syscall_64+0x1c4/0x4e0
     [<ffffffff83c32b2a>] entry_SYSCALL64_slow_path+0x25/0x25
    Code: e8 fc 42 7b fe 8b 0d 06 8a 50 03 49 0f af cf 48 85 c9 0f 88 7c 01 00 00 48 89 4d a8 e8 e0 42 7b fe 48 8b 45 c0 48 8b 4d a8 48 99 <48> f7 f9 49 01 c7 e8 cb 42 7b fe 48 8b 55 d0 48 b8 00 00 00 00
    RIP  [<ffffffff82c8bd9a>] snd_hrtimer_callback+0x1da/0x3f0
     RSP <ffff88011aa87da8>
    ---[ end trace 6aa380f756a21074 ]---

The problem happens when you call ioctl(SNDRV_TIMER_IOCTL_CONTINUE) on a completely new/unused timer -- it will have ->sticks == 0, which causes a divide by 0 in snd_hrtimer_callback().

---
 sound/core/timer.c |    1 +
 1 file changed, 1 insertion(+)

@@ -837,6 +837,7 @@ int snd_timer_new(struct snd_card *card,
 	timer->tmr_subdevice = tid->subdevice;
 	if (id)
 		strlcpy(timer->id, id, sizeof(timer->id));
+	timer->sticks = 1;
 	INIT_LIST_HEAD(&timer->device_list);
 	INIT_LIST_HEAD(&timer->open_list_head);
 	INIT_LIST_HEAD(&timer->active_list_head);

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Vegard Nossum <[email protected]>

commit 8ddc05638ee42b18ba4fe99b5fb647fa3ad20456 upstream.

I hit this with syzkaller:

    kasan: CONFIG_KASAN_INLINE enabled
    kasan: GPF could be caused by NULL-ptr deref or user memory access
    general protection fault: 0000 [#1] PREEMPT SMP KASAN
    CPU: 0 PID: 1327 Comm: a.out Not tainted 4.8.0-rc2+ #190
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
    task: ffff88011278d600 task.stack: ffff8801120c0000
    RIP: 0010:[<ffffffff82c8ba07>]  [<ffffffff82c8ba07>] snd_hrtimer_start+0x77/0x100
    RSP: 0018:ffff8801120c7a60  EFLAGS: 00010006
    RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000007
    RDX: 0000000000000009 RSI: 1ffff10023483091 RDI: 0000000000000048
    RBP: ffff8801120c7a78 R08: ffff88011a5cf768 R09: ffff88011a5ba790
    R10: 0000000000000002 R11: ffffed00234b9ef1 R12: ffff880114843980
    R13: ffffffff84213c00 R14: ffff880114843ab0 R15: 0000000000000286
    FS:  00007f72958f3700(0000) GS:ffff88011aa00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000603001 CR3: 00000001126ab000 CR4: 00000000000006f0
    Stack:
     ffff880114843980 ffff880111eb2dc0 ffff880114843a34 ffff8801120c7ad0
     ffffffff82c81ab1 0000000000000000 ffffffff842138e0 0000000100000000
     ffff880111eb2dd0 ffff880111eb2dc0 0000000000000001 ffff880111eb2dc0
    Call Trace:
     [<ffffffff82c81ab1>] snd_timer_start1+0x331/0x670
     [<ffffffff82c85bfd>] snd_timer_start+0x5d/0xa0
     [<ffffffff82c8795e>] snd_timer_user_ioctl+0x88e/0x2830
     [<ffffffff8159f3a0>] ? __follow_pte.isra.49+0x430/0x430
     [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80
     [<ffffffff815a26fa>] ? do_wp_page+0x3aa/0x1c90
     [<ffffffff8132762f>] ? put_prev_entity+0x108f/0x21a0
     [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80
     [<ffffffff816b0733>] do_vfs_ioctl+0x193/0x1050
     [<ffffffff813510af>] ? cpuacct_account_field+0x12f/0x1a0
     [<ffffffff816b05a0>] ? ioctl_preallocate+0x200/0x200
     [<ffffffff81002f2f>] ? syscall_trace_enter+0x3cf/0xdb0
     [<ffffffff815045ba>] ? __context_tracking_exit.part.4+0x9a/0x1e0
     [<ffffffff81002b60>] ? exit_to_usermode_loop+0x190/0x190
     [<ffffffff82001a97>] ? check_preemption_disabled+0x37/0x1e0
     [<ffffffff81d93889>] ? security_file_ioctl+0x89/0xb0
     [<ffffffff816b167f>] SyS_ioctl+0x8f/0xc0
     [<ffffffff816b15f0>] ? do_vfs_ioctl+0x1050/0x1050
     [<ffffffff81005524>] do_syscall_64+0x1c4/0x4e0
     [<ffffffff83c32b2a>] entry_SYSCALL64_slow_path+0x25/0x25
    Code: c7 c7 c4 b9 c8 82 48 89 d9 4c 89 ee e8 63 88 7f fe e8 7e 46 7b fe 48 8d 7b 48 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 84 c0 7e 65 80 7b 48 00 74 0e e8 52 46
    RIP  [<ffffffff82c8ba07>] snd_hrtimer_start+0x77/0x100
     RSP <ffff8801120c7a60>
    ---[ end trace 5955b08db7f2b029 ]---

This can happen if snd_hrtimer_open() fails to allocate memory and returns an error, which is currently not checked by snd_timer_open():

ioctl(SNDRV_TIMER_IOCTL_SELECT)
- snd_timer_user_tselect()
- snd_timer_close()
- snd_hrtimer_close()
- (struct snd_timer *) t->private_data = NULL
- snd_timer_open()
- snd_hrtimer_open()
- kzalloc() fails; t->private_data is still NULL

ioctl(SNDRV_TIMER_IOCTL_START)
- snd_timer_user_start()
- snd_timer_start()
- snd_timer_start1()
- snd_hrtimer_start()
- t->private_data == NULL // boom

---
 sound/core/timer.c |   17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

@@ -296,8 +296,21 @@ int snd_timer_open(struct snd_timer_inst
 		get_device(&timer->card->card_dev);
 	timeri->slave_class = tid->dev_sclass;
 	timeri->slave_id = slave_id;
-	if (list_empty(&timer->open_list_head) && timer->hw.open)
-		timer->hw.open(timer);
+
+	if (list_empty(&timer->open_list_head) && timer->hw.open) {
+		int err = timer->hw.open(timer);
+		if (err) {
+			kfree(timeri->owner);
+			kfree(timeri);
+
+			if (timer->card)
+				put_device(&timer->card->card_dev);
+			module_put(timer->module);
+			mutex_unlock(&register_mutex);
+			return err;
+		}
+	}
+
 	list_add_tail(&timeri->open_list, &timer->open_list_head);
 	snd_timer_check_master(timeri);
 	mutex_unlock(&register_mutex);

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Tyrel Datwyler <[email protected]>

commit a87eeb900dbb9f8202f96604d56e47e67c936b9d upstream.

Commit 655ee63cf371 ("scsi constants: command, sense key + additional sense string") added a "Completed" sense string with key 0xF to snstext[], but failed to updated the upper bounds check of the sense key in scsi_sense_key_string().

---
 drivers/scsi/constants.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

@@ -1181,8 +1181,9 @@ static const char * const snstext[] = {
 
 /* Get sense key string or NULL if not available */
 const char *
-scsi_sense_key_string(unsigned char key) {
-	if (key <= 0xE)
+scsi_sense_key_string(unsigned char key)
+{
+	if (key < ARRAY_SIZE(snstext))
 		return snstext[key];
 	return NULL;
 }

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: James Hogan <[email protected]>

commit 096a8b6d5e7ab9f8ca3d2474b3ca6a1fe79e0371 upstream.

The argument i of atomic_*_return() operations is given to inline asm with the "bd" constraint, which means "An Op2 register where Op1 is a data unit register and the instruction supports O2R", however Op1 is constrained by "da" which allows an address unit register to be used.

Fix the constraint to use "br", meaning "An Op2 register and the instruction supports O2R", i.e. not requiring Op1 to be a data unit register.

---
 arch/metag/include/asm/atomic_lnkget.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -61,7 +61,7 @@ static inline int atomic_##op##_return(i
 		"	CMPT	%0, #HI(0x02000000)\n"			\
 		"	BNZ 1b\n"					\
 		: "=&d" (temp), "=&da" (result)				\
-		: "da" (&v->counter), "bd" (i)				\
+		: "da" (&v->counter), "br" (i)				\
 		: "cc");						\
 									\
 	smp_mb();							\

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Sai Gurrappadi <[email protected]>

commit e43e94c1eda76dabd686ddf6f7825f54d747b310 upstream.

Currently, the userspace governor only updates frequency on GOV_LIMITS if policy->cur falls outside policy->{min/max}. However, it is also necessary to update current frequency on GOV_LIMITS to match the user requested value if it can be achieved within the new policy->{max/min}.

This was previously the behaviour in the governor until commit d1922f0 ("cpufreq: Simplify userspace governor") which incorrectly assumed that policy->cur == user requested frequency via scaling_setspeed. This won't be true if the user requested frequency falls outside policy->{min/max}.
Ex: a temporary thermal cap throttled the user requested frequency.

Fix this by storing the user requested frequency in a seperate variable. The governor will then try to achieve this request on every GOV_LIMITS change.

---
 drivers/cpufreq/cpufreq_userspace.c |   43 +++++++++++++++++++++++++++++++-----
 1 file changed, 38 insertions(+), 5 deletions(-)

@@ -17,6 +17,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/slab.h>
 
 static DEFINE_PER_CPU(unsigned int, cpu_is_managed);
 static DEFINE_MUTEX(userspace_mutex);

@@ -31,6 +32,7 @@ static DEFINE_MUTEX(userspace_mutex);
 static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
 {
 	int ret = -EINVAL;
+	unsigned int *setspeed = policy->governor_data;
 
 	pr_debug("cpufreq_set for cpu %u, freq %u kHz\n", policy->cpu, freq);
 

@@ -38,6 +40,8 @@ static int cpufreq_set(struct cpufreq_po
 	if (!per_cpu(cpu_is_managed, policy->cpu))
 		goto err;
 
+	*setspeed = freq;
+
 	ret = __cpufreq_driver_target(policy, freq, CPUFREQ_RELATION_L);
  err:
 	mutex_unlock(&userspace_mutex);

@@ -49,19 +53,45 @@ static ssize_t show_speed(struct cpufreq
 	return sprintf(buf, "%u\n", policy->cur);
 }
 
+static int cpufreq_userspace_policy_init(struct cpufreq_policy *policy)
+{
+	unsigned int *setspeed;
+
+	setspeed = kzalloc(sizeof(*setspeed), GFP_KERNEL);
+	if (!setspeed)
+		return -ENOMEM;
+
+	policy->governor_data = setspeed;
+	return 0;
+}
+
 static int cpufreq_governor_userspace(struct cpufreq_policy *policy,
 				   unsigned int event)
 {
+	unsigned int *setspeed = policy->governor_data;
 	unsigned int cpu = policy->cpu;
 	int rc = 0;
 
+	if (event == CPUFREQ_GOV_POLICY_INIT)
+		return cpufreq_userspace_policy_init(policy);
+
+	if (!setspeed)
+		return -EINVAL;
+
 	switch (event) {
+	case CPUFREQ_GOV_POLICY_EXIT:
+		mutex_lock(&userspace_mutex);
+		policy->governor_data = NULL;
+		kfree(setspeed);
+		mutex_unlock(&userspace_mutex);
+		break;
 	case CPUFREQ_GOV_START:
 		BUG_ON(!policy->cur);
 		pr_debug("started managing cpu %u\n", cpu);
 
 		mutex_lock(&userspace_mutex);
 		per_cpu(cpu_is_managed, cpu) = 1;
+		*setspeed = policy->cur;
 		mutex_unlock(&userspace_mutex);
 		break;
 	case CPUFREQ_GOV_STOP:

@@ -69,20 +99,23 @@ static int cpufreq_governor_userspace(st
 
 		mutex_lock(&userspace_mutex);
 		per_cpu(cpu_is_managed, cpu) = 0;
+		*setspeed = 0;
 		mutex_unlock(&userspace_mutex);
 		break;
 	case CPUFREQ_GOV_LIMITS:
 		mutex_lock(&userspace_mutex);
-		pr_debug("limit event for cpu %u: %u - %u kHz, currently %u kHz\n",
-			cpu, policy->min, policy->max,
-			policy->cur);
+		pr_debug("limit event for cpu %u: %u - %u kHz, currently %u kHz, last set to %u kHz\n",
+			cpu, policy->min, policy->max, policy->cur, *setspeed);
 
-		if (policy->max < policy->cur)
+		if (policy->max < *setspeed)
 			__cpufreq_driver_target(policy, policy->max,
 						CPUFREQ_RELATION_H);
-		else if (policy->min > policy->cur)
+		else if (policy->min > *setspeed)
 			__cpufreq_driver_target(policy, policy->min,
 						CPUFREQ_RELATION_L);
+		else
+			__cpufreq_driver_target(policy, *setspeed,
+						CPUFREQ_RELATION_L);
 		mutex_unlock(&userspace_mutex);
 		break;
 	}

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Krzysztof Kozlowski <[email protected]>

commit 48a61e1e2af8020f11a2b8f8dc878144477623c6 upstream.

Add proper error path (for disabling runtime PM) when registering of hwrng fails.

---
 drivers/char/hw_random/exynos-rng.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

@@ -118,6 +118,7 @@ static int exynos_rng_probe(struct platf
 {
 	struct exynos_rng *exynos_rng;
 	struct resource *res;
+	int ret;
 
 	exynos_rng = devm_kzalloc(&pdev->dev, sizeof(struct exynos_rng),
 					GFP_KERNEL);

@@ -145,7 +146,13 @@ static int exynos_rng_probe(struct platf
 	pm_runtime_use_autosuspend(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
 
-	return devm_hwrng_register(&pdev->dev, &exynos_rng->rng);
+	ret = devm_hwrng_register(&pdev->dev, &exynos_rng->rng);
+	if (ret) {
+		pm_runtime_dont_use_autosuspend(&pdev->dev);
+		pm_runtime_disable(&pdev->dev);
+	}
+
+	return ret;
 }
 
 #ifdef CONFIG_PM

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Nicolai Stange <[email protected]>

commit f2d1362ff7d266b3d2b1c764d6c2ef4a3b457f23 upstream.

Currently, if the number of leading zeros is greater than fits into a complete limb, mpi_write_sgl() skips them by iterating over them limb-wise.

However, it fails to adjust its internal leading zeros tracking variable, lzeros, accordingly: it does a

  p -= sizeof(alimb);
  continue;

which should really have been a

  lzeros -= sizeof(alimb);
  continue;

Since lzeros never decreases if its initial value >= sizeof(alimb), nothing gets copied by mpi_write_sgl() in that case.

Instead of skipping the high order zero limbs within the loop as shown above, fix the issue by adjusting the copying loop's bounds.

---
 lib/mpi/mpicoder.c |   21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

@@ -367,7 +367,9 @@ int mpi_write_to_sgl(MPI a, struct scatt
 	buf_len = sgl->length;
 	p2 = sg_virt(sgl);
 
-	for (i = a->nlimbs - 1; i >= 0; i--) {
+	for (i = a->nlimbs - 1 - lzeros / BYTES_PER_MPI_LIMB,
+			lzeros %= BYTES_PER_MPI_LIMB;
+		i >= 0; i--) {
 		alimb = a->d[i];
 		p = (u8 *)&alimb2;
 #if BYTES_PER_MPI_LIMB == 4

@@ -388,17 +390,12 @@ int mpi_write_to_sgl(MPI a, struct scatt
 #error please implement for this limb size.
 #endif
 		if (lzeros > 0) {
-			if (lzeros >= sizeof(alimb)) {
-				p -= sizeof(alimb);
-				continue;
-			} else {
-				mpi_limb_t *limb1 = (void *)p - sizeof(alimb);
-				mpi_limb_t *limb2 = (void *)p - sizeof(alimb)
-							+ lzeros;
-				*limb1 = *limb2;
-				p -= lzeros;
-				y = lzeros;
-			}
+			mpi_limb_t *limb1 = (void *)p - sizeof(alimb);
+			mpi_limb_t *limb2 = (void *)p - sizeof(alimb)
+				+ lzeros;
+			*limb1 = *limb2;
+			p -= lzeros;
+			y = lzeros;
 			lzeros -= sizeof(alimb);
 		}
 

Build results:

	total: 149 pass: 149 fail: 0
Qemu test results:
	total: 101 pass: 101 fail: 0

Details are available at http://kerneltests.org/builders.

Guenter

Compiled and booted on my test system. No dmesg regressions.

thanks,
-- Shuah

Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America(Silicon Valley)
[email protected]

[...]

Most of them have an extra '[PATCH ...]' in the subject; please make sure to remove that before committing them.

Ben.

Ben Hutchings
Software Developer, Codethink Ltd.

Yeah, that was my mistake, will fix that up before committing.

thanks,

greg k-h