4.9.18-stable review

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

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

From: Eric Anholt <[email protected]>

commit 457e67a728696c4f8e6423c64e93def50530db9a upstream.

The loop is scanning until the original max_ip (size of the BO), but we want to not examine any code after the PROG_END's delay slots. There was a block trying to do that, except that we had some early continue statements if the signal wasn't a PROG_END or a BRANCH.

The failure mode would be that a valid shader is rejected because some undefined memory after the PROG_END slots is parsed as a branch and the rest of its setup is illegal. I haven't seen this in the wild, but valgrind was complaining when about this up in the userland simulator mode.

---
 drivers/gpu/drm/vc4/vc4_validate_shaders.c |   19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

@@ -608,9 +608,7 @@ static bool
 vc4_validate_branches(struct vc4_shader_validation_state *validation_state)
 {
 	uint32_t max_branch_target = 0;
-	bool found_shader_end = false;
 	int ip;
-	int shader_end_ip = 0;
 	int last_branch = -2;
 
 	for (ip = 0; ip < validation_state->max_ip; ip++) {

@@ -621,8 +619,13 @@ vc4_validate_branches(struct vc4_shader_
 		uint32_t branch_target_ip;
 
 		if (sig == QPU_SIG_PROG_END) {
-			shader_end_ip = ip;
-			found_shader_end = true;
+			/* There are two delay slots after program end is
+			 * signaled that are still executed, then we're
+			 * finished.  validation_state->max_ip is the
+			 * instruction after the last valid instruction in the
+			 * program.
+			 */
+			validation_state->max_ip = ip + 3;
 			continue;
 		}
 

@@ -676,15 +679,9 @@ vc4_validate_branches(struct vc4_shader_
 		}
 		set_bit(after_delay_ip, validation_state->branch_targets);
 		max_branch_target = max(max_branch_target, after_delay_ip);
-
-		/* There are two delay slots after program end is signaled
-		 * that are still executed, then we're finished.
-		 */
-		if (found_shader_end && ip == shader_end_ip + 2)
-			break;
 	}
 
-	if (max_branch_target > shader_end_ip) {
+	if (max_branch_target > validation_state->max_ip - 3) {
 		DRM_ERROR("Branch landed after QPU_SIG_PROG_END");
 		return false;
 	}

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

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

From: Chuck Lever <[email protected]>

commit eed50879d64ab1b9f76445dbab822e43a098b309 upstream.

New complaint from kbuild for 4.9.y:

net/sunrpc/xprtrdma/verbs.c:489:19: sparse: incompatible types in
comparison expression (different type sizes)

verbs.c:
489 max_sge = min(ia->ri_device->attrs.max_sge, RPCRDMA_MAX_SEND_SGES);

I can't reproduce this running sparse here. Likewise, "make W=1 net/sunrpc/xprtrdma/verbs.o" never indicated any issue.

A little poking suggests that because the range of its values is small, gcc can make the actual width of RPCRDMA_MAX_SEND_SGES smaller than the width of an unsigned integer.

---
 net/sunrpc/xprtrdma/verbs.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -486,7 +486,8 @@ rpcrdma_ep_create(struct rpcrdma_ep *ep,
 	struct ib_cq *sendcq, *recvcq;
 	int rc;
 
-	max_sge = min(ia->ri_device->attrs.max_sge, RPCRDMA_MAX_SEND_SGES);
+	max_sge = min_t(unsigned int, ia->ri_device->attrs.max_sge,
+			RPCRDMA_MAX_SEND_SGES);
 	if (max_sge < RPCRDMA_MIN_SEND_SGES) {
 		pr_warn("rpcrdma: HCA provides only %d send SGEs\n", max_sge);
 		return -ENOMEM;

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

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

From: Olga Kornievskaia <[email protected]>

commit 63513232f8cd219dcaa5eafae028740ed3067d83 upstream.

Since rpc_task is async, the release function should be called which will free the impl_id, scope, and owner.

Trond pointed at 2 more problems:
-- use of client pointer after free in the nfs4_exchangeid_release() function -- cl_count mismatch if rpc_run_task() isn't run

---
 fs/nfs/nfs4proc.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

@@ -7426,11 +7426,11 @@ static void nfs4_exchange_id_release(voi
 	struct nfs41_exchange_id_data *cdata =
 					(struct nfs41_exchange_id_data *)data;
 
-	nfs_put_client(cdata->args.client);
 	if (cdata->xprt) {
 		xprt_put(cdata->xprt);
 		rpc_clnt_xprt_switch_put(cdata->args.client->cl_rpcclient);
 	}
+	nfs_put_client(cdata->args.client);
 	kfree(cdata->res.impl_id);
 	kfree(cdata->res.server_scope);
 	kfree(cdata->res.server_owner);

@@ -7537,10 +7537,8 @@ static int _nfs4_proc_exchange_id(struct
 	task_setup_data.callback_data = calldata;
 
 	task = rpc_run_task(&task_setup_data);
-	if (IS_ERR(task)) {
-	status = PTR_ERR(task);
-		goto out_impl_id;
-	}
+	if (IS_ERR(task))
+		return PTR_ERR(task);
 
 	if (!xprt) {
 		status = rpc_wait_for_completion_task(task);

@@ -7568,6 +7566,7 @@ out_server_owner:
 	kfree(calldata->res.server_owner);
 out_calldata:
 	kfree(calldata);
+	nfs_put_client(clp);
 	goto out;
 }
 

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

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

From: Rafael J. Wysocki <[email protected]>

commit 9b4f603e7a9f4282aec451063ffbbb8bb410dcd9 upstream.

There is a missing newline in show_cpuinfo_cur_freq(), so add it, but while at it clean that function up somewhat too.

---
 drivers/cpufreq/cpufreq.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

@@ -680,9 +680,11 @@ static ssize_t show_cpuinfo_cur_freq(str
 					char *buf)
 {
 	unsigned int cur_freq = __cpufreq_get(policy);
-	if (!cur_freq)
-		return sprintf(buf, "<unknown>");
-	return sprintf(buf, "%u\n", cur_freq);
+
+	if (cur_freq)
+		return sprintf(buf, "%u\n", cur_freq);
+
+	return sprintf(buf, "<unknown>\n");
 }
 
 /**

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

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

From: Michael Ellerman <[email protected]>

commit 97ee351b50a49717543533cfb85b4bf9d88c9680 upstream.

Recent toolchains force the TOC to be 256 byte aligned. We need to enforce this alignment in the zImage linker script, otherwise pointers to our TOC variables (__toc_start) could be incorrect. If the actual start of the TOC and __toc_start don't have the same value we crash early in the zImage wrapper.

---
 arch/powerpc/boot/zImage.lds.S |    1 +
 1 file changed, 1 insertion(+)

@@ -68,6 +68,7 @@ SECTIONS
   }
 
 #ifdef CONFIG_PPC64_BOOT_WRAPPER
+  . = ALIGN(256);
   .got :
   {
     __toc_start = .;

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

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

From: Shaohua Li <[email protected]>

commit 61eb2b43b99ebdc9bc6bc83d9792257b243e7cb3 upstream.

Neil Brown pointed out a potential deadlock in raid 10 code with bio_split/chain. The raid1 code could have the same issue, but recent barrier rework makes it less likely to happen. The deadlock happens in below sequence:

1. generic_make_request(bio), this will set current->bio_list
2. raid10_make_request will split bio to bio1 and bio2
3. __make_request(bio1), wait_barrer, add underlayer disk bio to current->bio_list
4. __make_request(bio2), wait_barrer

If raise_barrier happens between 3 & 4, since wait_barrier runs at 3, raise_barrier waits for IO completion from 3. And since raise_barrier sets barrier, 4 waits for raise_barrier. But IO from 3 can't be dispatched because raid10_make_request() doesn't finished yet.

The solution is to adjust the IO ordering. Quotes from Neil:
"
It is much safer to:

    if (need to split) {
        split = bio_split(bio, ...)
        bio_chain(...)
        make_request_fn(split);
        generic_make_request(bio);
   } else
        make_request_fn(mddev, bio);

This way we first process the initial section of the bio (in 'split') which will queue some requests to the underlying devices. These requests will be queued in generic_make_request.
Then we queue the remainder of the bio, which will be added to the end of the generic_make_request queue.
Then we return.
generic_make_request() will pop the lower-level device requests off the queue and handle them first. Then it will process the remainder of the original bio once the first section has been fully processed. "

Note, this only happens in read path. In write path, the bio is flushed to underlaying disks either by blk flush (from schedule) or offladed to raid1/10d. It's queued in current->bio_list.

---
 drivers/md/raid10.c |   18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

@@ -1470,7 +1470,25 @@ static void raid10_make_request(struct m
 			split = bio;
 		}
 
+		/*
+		 * If a bio is splitted, the first part of bio will pass
+		 * barrier but the bio is queued in current->bio_list (see
+		 * generic_make_request). If there is a raise_barrier() called
+		 * here, the second part of bio can't pass barrier. But since
+		 * the first part bio isn't dispatched to underlaying disks
+		 * yet, the barrier is never released, hence raise_barrier will
+		 * alays wait. We have a deadlock.
+		 * Note, this only happens in read path. For write path, the
+		 * first part of bio is dispatched in a schedule() call
+		 * (because of blk plug) or offloaded to raid10d.
+		 * Quitting from the function immediately can change the bio
+		 * order queued in bio_list and avoid the deadlock.
+		 */
 		__make_request(mddev, split);
+		if (split != bio && bio_data_dir(bio) == READ) {
+			generic_make_request(bio);
+			break;
+		}
 	} while (split != bio);
 
 	/* In case raid10d snuck in to freeze_array */

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

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

From: Chris Leech <[email protected]>

commit 6f8830f5bbab16e54f261de187f3df4644a5b977 upstream.

There's a rather long standing regression from the commit "libiscsi:
Reduce locking contention in fast path"

Depending on iSCSI target behavior, it's possible to hit the case in iscsi_complete_task where the task is still on a pending list (!list_empty(&task->running)). When that happens the task is removed from the list while holding the session back_lock, but other task list modification occur under the frwd_lock. That leads to linked list corruption and eventually a panicked system.

Rather than back out the session lock split entirely, in order to try and keep some of the performance gains this patch adds another lock to maintain the task lists integrity.

Major enterprise supported kernels have been backing out the lock split for while now, thanks to the efforts at IBM where a lab setup has the most reliable reproducer I've seen on this issue. This patch has been tested there successfully.

---
 drivers/scsi/libiscsi.c |   26 +++++++++++++++++++++++++-
 include/scsi/libiscsi.h |    1 +
 2 files changed, 26 insertions(+), 1 deletion(-)

@@ -560,8 +560,12 @@ static void iscsi_complete_task(struct i
 	WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
 	task->state = state;
 
-	if (!list_empty(&task->running))
+	spin_lock_bh(&conn->taskqueuelock);
+	if (!list_empty(&task->running)) {
+		pr_debug_once("%s while task on list", __func__);
 		list_del_init(&task->running);
+	}
+	spin_unlock_bh(&conn->taskqueuelock);
 
 	if (conn->task == task)
 		conn->task = NULL;

@@ -783,7 +787,9 @@ __iscsi_conn_send_pdu(struct iscsi_conn
 		if (session->tt->xmit_task(task))
 			goto free_task;
 	} else {
+		spin_lock_bh(&conn->taskqueuelock);
 		list_add_tail(&task->running, &conn->mgmtqueue);
+		spin_unlock_bh(&conn->taskqueuelock);
 		iscsi_conn_queue_work(conn);
 	}
 

@@ -1474,8 +1480,10 @@ void iscsi_requeue_task(struct iscsi_tas
 	 * this may be on the requeue list already if the xmit_task callout
 	 * is handling the r2ts while we are adding new ones
 	 */
+	spin_lock_bh(&conn->taskqueuelock);
 	if (list_empty(&task->running))
 		list_add_tail(&task->running, &conn->requeue);
+	spin_unlock_bh(&conn->taskqueuelock);
 	iscsi_conn_queue_work(conn);
 }
 EXPORT_SYMBOL_GPL(iscsi_requeue_task);

@@ -1512,22 +1520,26 @@ static int iscsi_data_xmit(struct iscsi_
 	 * only have one nop-out as a ping from us and targets should not
 	 * overflow us with nop-ins
 	 */
+	spin_lock_bh(&conn->taskqueuelock);
 check_mgmt:
 	while (!list_empty(&conn->mgmtqueue)) {
 		conn->task = list_entry(conn->mgmtqueue.next,
 					 struct iscsi_task, running);
 		list_del_init(&conn->task->running);
+		spin_unlock_bh(&conn->taskqueuelock);
 		if (iscsi_prep_mgmt_task(conn, conn->task)) {
 			/* regular RX path uses back_lock */
 			spin_lock_bh(&conn->session->back_lock);
 			__iscsi_put_task(conn->task);
 			spin_unlock_bh(&conn->session->back_lock);
 			conn->task = NULL;
+			spin_lock_bh(&conn->taskqueuelock);
 			continue;
 		}
 		rc = iscsi_xmit_task(conn);
 		if (rc)
 			goto done;
+		spin_lock_bh(&conn->taskqueuelock);
 	}
 
 	/* process pending command queue */

@@ -1535,19 +1547,24 @@ check_mgmt:
 		conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
 					running);
 		list_del_init(&conn->task->running);
+		spin_unlock_bh(&conn->taskqueuelock);
 		if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
 			fail_scsi_task(conn->task, DID_IMM_RETRY);
+			spin_lock_bh(&conn->taskqueuelock);
 			continue;
 		}
 		rc = iscsi_prep_scsi_cmd_pdu(conn->task);
 		if (rc) {
 			if (rc == -ENOMEM || rc == -EACCES) {
+				spin_lock_bh(&conn->taskqueuelock);
 				list_add_tail(&conn->task->running,
 					      &conn->cmdqueue);
 				conn->task = NULL;
+				spin_unlock_bh(&conn->taskqueuelock);
 				goto done;
 			} else
 				fail_scsi_task(conn->task, DID_ABORT);
+			spin_lock_bh(&conn->taskqueuelock);
 			continue;
 		}
 		rc = iscsi_xmit_task(conn);

@@ -1558,6 +1575,7 @@ check_mgmt:
 		 * we need to check the mgmt queue for nops that need to
 		 * be sent to aviod starvation
 		 */
+		spin_lock_bh(&conn->taskqueuelock);
 		if (!list_empty(&conn->mgmtqueue))
 			goto check_mgmt;
 	}

@@ -1577,12 +1595,15 @@ check_mgmt:
 		conn->task = task;
 		list_del_init(&conn->task->running);
 		conn->task->state = ISCSI_TASK_RUNNING;
+		spin_unlock_bh(&conn->taskqueuelock);
 		rc = iscsi_xmit_task(conn);
 		if (rc)
 			goto done;
+		spin_lock_bh(&conn->taskqueuelock);
 		if (!list_empty(&conn->mgmtqueue))
 			goto check_mgmt;
 	}
+	spin_unlock_bh(&conn->taskqueuelock);
 	spin_unlock_bh(&conn->session->frwd_lock);
 	return -ENODATA;
 

@@ -1738,7 +1759,9 @@ int iscsi_queuecommand(struct Scsi_Host
 			goto prepd_reject;
 		}
 	} else {
+		spin_lock_bh(&conn->taskqueuelock);
 		list_add_tail(&task->running, &conn->cmdqueue);
+		spin_unlock_bh(&conn->taskqueuelock);
 		iscsi_conn_queue_work(conn);
 	}
 

@@ -2897,6 +2920,7 @@ iscsi_conn_setup(struct iscsi_cls_sessio
 	INIT_LIST_HEAD(&conn->mgmtqueue);
 	INIT_LIST_HEAD(&conn->cmdqueue);
 	INIT_LIST_HEAD(&conn->requeue);
+	spin_lock_init(&conn->taskqueuelock);
 	INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
 
 	/* allocate login_task used for the login/text sequences */

@@ -196,6 +196,7 @@ struct iscsi_conn {
 	struct iscsi_task	*task;		/* xmit task in progress */
 
 	/* xmit */
+	spinlock_t		taskqueuelock;  /* protects the next three lists */
 	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
 	struct list_head	cmdqueue;	/* data-path cmd queue */
 	struct list_head	requeue;	/* tasks needing another run */

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

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

From: Max Lohrmann <[email protected]>

commit 13603685c1f12c67a7a2427f00b63f39a2b6f7c9 upstream.

As reported by Max, the Windows 2008 R2 chkdsk utility expects VERIFY_16 to be supported, and does not handle the returned CHECK_CONDITION properly, resulting in an infinite loop.

The kernel will log huge amounts of this error:

kernel: TARGET_CORE[iSCSI]: Unsupported SCSI Opcode 0x8f, sending CHECK_CONDITION.

---
 drivers/target/target_core_sbc.c |   10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

@@ -1104,9 +1104,15 @@ sbc_parse_cdb(struct se_cmd *cmd, struct
 			return ret;
 		break;
 	case VERIFY:
+	case VERIFY_16:
 		size = 0;
-		sectors = transport_get_sectors_10(cdb);
-		cmd->t_task_lba = transport_lba_32(cdb);
+		if (cdb[0] == VERIFY) {
+			sectors = transport_get_sectors_10(cdb);
+			cmd->t_task_lba = transport_lba_32(cdb);
+		} else {
+			sectors = transport_get_sectors_16(cdb);
+			cmd->t_task_lba = transport_lba_64(cdb);
+		}
 		cmd->execute_cmd = sbc_emulate_noop;
 		goto check_lba;
 	case REZERO_UNIT:

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

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

From: Andreas Gruenbacher <[email protected]>

commit 28ea06c46fbcab63fd9a55531387b7928a18a590 upstream.

Commit 88ffbf3e03 switches to using rhashtables for glocks, hashing over the entire struct lm_lockname instead of its individual fields. On some architectures, struct lm_lockname contains a hole of uninitialized memory due to alignment rules, which now leads to incorrect hash values. Get rid of that hole.

---
 fs/gfs2/incore.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -207,7 +207,7 @@ struct lm_lockname {
 	struct gfs2_sbd *ln_sbd;
 	u64 ln_number;
 	unsigned int ln_type;
-};
+} __packed __aligned(sizeof(int));
 
 #define lm_name_equal(name1, name2) \
         (((name1)->ln_number == (name2)->ln_number) &&	\

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

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

From: Linus Torvalds <[email protected]>

commit 474c90156c8dcc2fa815e6716cc9394d7930cb9c upstream.

gcc-7 has an "optimization" pass that completely screws up, and generates the code expansion for the (impossible) case of calling ilog2() with a zero constant, even when the code gcc compiles does not actually have a zero constant.

And we try to generate a compile-time error for anybody doing ilog2() on a constant where that doesn't make sense (be it zero or negative). So now gcc7 will fail the build due to our sanity checking, because it created that constant-zero case that didn't actually exist in the source code.

There's a whole long discussion on the kernel mailing about how to work around this gcc bug. The gcc people themselevs have discussed their "feature" in

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72785

but it's all water under the bridge, because while it looked at one point like it would be solved by the time gcc7 was released, that was not to be.

So now we have to deal with this compiler braindamage.

And the only simple approach seems to be to just delete the code that tries to warn about bad uses of ilog2().

So now "ilog2()" will just return 0 not just for the value 1, but for any non-positive value too.

It's not like I can recall anybody having ever actually tried to use this function on any invalid value, but maybe the sanity check just meant that such code never made it out in public.

---
 include/linux/log2.h       |   13 ++-----------
 tools/include/linux/log2.h |   13 ++-----------
 2 files changed, 4 insertions(+), 22 deletions(-)

@@ -16,12 +16,6 @@
 #include <linux/bitops.h>
 
 /*
- * deal with unrepresentable constant logarithms
- */
-extern __attribute__((const, noreturn))
-int ____ilog2_NaN(void);
-
-/*
  * non-constant log of base 2 calculators
  * - the arch may override these in asm/bitops.h if they can be implemented
  *   more efficiently than using fls() and fls64()

@@ -85,7 +79,7 @@ unsigned long __rounddown_pow_of_two(uns
 #define ilog2(n)				\
 (						\
 	__builtin_constant_p(n) ? (		\
-		(n) < 1 ? ____ilog2_NaN() :	\
+		(n) < 2 ? 0 :			\
 		(n) & (1ULL << 63) ? 63 :	\
 		(n) & (1ULL << 62) ? 62 :	\
 		(n) & (1ULL << 61) ? 61 :	\

@@ -148,10 +142,7 @@ unsigned long __rounddown_pow_of_two(uns
 		(n) & (1ULL <<  4) ?  4 :	\
 		(n) & (1ULL <<  3) ?  3 :	\
 		(n) & (1ULL <<  2) ?  2 :	\
-		(n) & (1ULL <<  1) ?  1 :	\
-		(n) & (1ULL <<  0) ?  0 :	\
-		____ilog2_NaN()			\
-				   ) :		\
+		1 ) :				\
 	(sizeof(n) <= 4) ?			\
 	__ilog2_u32(n) :			\
 	__ilog2_u64(n)				\

@@ -13,12 +13,6 @@
 #define _TOOLS_LINUX_LOG2_H
 
 /*
- * deal with unrepresentable constant logarithms
- */
-extern __attribute__((const, noreturn))
-int ____ilog2_NaN(void);
-
-/*
  * non-constant log of base 2 calculators
  * - the arch may override these in asm/bitops.h if they can be implemented
  *   more efficiently than using fls() and fls64()

@@ -78,7 +72,7 @@ unsigned long __rounddown_pow_of_two(uns
 #define ilog2(n)				\
 (						\
 	__builtin_constant_p(n) ? (		\
-		(n) < 1 ? ____ilog2_NaN() :	\
+		(n) < 2 ? 0 :			\
 		(n) & (1ULL << 63) ? 63 :	\
 		(n) & (1ULL << 62) ? 62 :	\
 		(n) & (1ULL << 61) ? 61 :	\

@@ -141,10 +135,7 @@ unsigned long __rounddown_pow_of_two(uns
 		(n) & (1ULL <<  4) ?  4 :	\
 		(n) & (1ULL <<  3) ?  3 :	\
 		(n) & (1ULL <<  2) ?  2 :	\
-		(n) & (1ULL <<  1) ?  1 :	\
-		(n) & (1ULL <<  0) ?  0 :	\
-		____ilog2_NaN()			\
-				   ) :		\
+		1 ) :				\
 	(sizeof(n) <= 4) ?			\
 	__ilog2_u32(n) :			\
 	__ilog2_u64(n)				\

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

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

From: Tejun Heo <[email protected]>

commit 1d18c2747f937f1b5ec65ce6bf4ccb9ca1aea9e8 upstream.

pids_can_fork() is special in that the css association is guaranteed to be stable throughout the function and thus doesn't need RCU protection around task_css access. When determining the css to charge the pid, task_css_check() is used to override the RCU sanity check.

While adding a warning message on fork rejection from pids limit, 135b8b37bd91 ("cgroup: Add pids controller event when fork fails because of pid limit") incorrectly added a task_css access which is neither RCU protected or explicitly annotated. This triggers the following suspicious RCU usage warning when RCU debugging is enabled.

cgroup: fork rejected by pids controller in

===============================
[ ERR: suspicious RCU usage. ]
4.10.0-work+ #1 Not tainted
-------------------------------
./include/linux/cgroup.h:435 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 0
1 lock held by bash/1748:
#0: (&cgroup_threadgroup_rwsem){+++++.}, at: [<ffffffff81052c96>] _do_fork+0xe6/0x6e0

  stack backtrace:
  CPU: 3 PID: 1748 Comm: bash Not tainted 4.10.0-work+ #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-1.fc25 04/01/2014
  Call Trace:
   dump_stack+0x68/0x93
   lockdep_rcu_suspicious+0xd7/0x110
   pids_can_fork+0x1c7/0x1d0
   cgroup_can_fork+0x67/0xc0
   copy_process.part.58+0x1709/0x1e90
   _do_fork+0xe6/0x6e0
   SyS_clone+0x19/0x20
   do_syscall_64+0x5c/0x140
   entry_SYSCALL64_slow_path+0x25/0x25
  RIP: 0033:0x7f7853fab93a
  RSP: 002b:00007ffc12d05c90 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
  RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7853fab93a
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
  RBP: 00007ffc12d05cc0 R08: 0000000000000000 R09: 00007f78548db700
  R10: 00007f78548db9d0 R11: 0000000000000246 R12: 00000000000006d4
  R13: 0000000000000001 R14: 0000000000000000 R15: 000055e3ebe2c04d
  /asdf

There's no reason to dereference task_css again here when the associated css is already available. Fix it by replacing the task_cgroup() call with css->cgroup.

---
 kernel/cgroup_pids.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -229,7 +229,7 @@ static int pids_can_fork(struct task_str
 		/* Only log the first time events_limit is incremented. */
 		if (atomic64_inc_return(&pids->events_limit) == 1) {
 			pr_info("cgroup: fork rejected by pids controller in ");
-			pr_cont_cgroup_path(task_cgroup(current, pids_cgrp_id));
+			pr_cont_cgroup_path(css->cgroup);
 			pr_cont("\n");
 		}
 		cgroup_file_notify(&pids->events_file);

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

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

From: Quinn Tran <[email protected]>

commit 8b666809e10cda9814af3e8be339d35b83909056 upstream.

When FW notify driver or driver detects low FW resource, driver tries to send out Busy SCSI Status to tell Initiator side to back off. During the send process, the lock was not held.

---
 drivers/scsi/qla2xxx/qla_target.c |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

@@ -5375,16 +5375,22 @@ qlt_send_busy(struct scsi_qla_host *vha,
 
 static int
 qlt_chk_qfull_thresh_hold(struct scsi_qla_host *vha,
-	struct atio_from_isp *atio)
+	struct atio_from_isp *atio, bool ha_locked)
 {
 	struct qla_hw_data *ha = vha->hw;
 	uint16_t status;
+	unsigned long flags;
 
 	if (ha->tgt.num_pend_cmds < Q_FULL_THRESH_HOLD(ha))
 		return 0;
 
+	if (!ha_locked)
+		spin_lock_irqsave(&ha->hardware_lock, flags);
 	status = temp_sam_status;
 	qlt_send_busy(vha, atio, status);
+	if (!ha_locked)
+		spin_unlock_irqrestore(&ha->hardware_lock, flags);
+
 	return 1;
 }
 

@@ -5429,7 +5435,7 @@ static void qlt_24xx_atio_pkt(struct scs
 
 
 		if (likely(atio->u.isp24.fcp_cmnd.task_mgmt_flags == 0)) {
-			rc = qlt_chk_qfull_thresh_hold(vha, atio);
+			rc = qlt_chk_qfull_thresh_hold(vha, atio, ha_locked);
 			if (rc != 0) {
 				tgt->atio_irq_cmd_count--;
 				return;

@@ -5552,7 +5558,7 @@ static void qlt_response_pkt(struct scsi
 			break;
 		}
 
-		rc = qlt_chk_qfull_thresh_hold(vha, atio);
+		rc = qlt_chk_qfull_thresh_hold(vha, atio, true);
 		if (rc != 0) {
 			tgt->irq_cmd_count--;
 			return;

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

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

From: Nicholas Bellinger <[email protected]>

commit a04e54f2c35823ca32d56afcd5cea5b783e2f51a upstream.

The following fixes a divide by zero OOPs with TYPE_TAPE due to pscsi_tape_read_blocksize() failing causing a zero sd->sector_size being propigated up via dev_attrib.hw_block_size.

It also fixes another long-standing bug where TYPE_TAPE and TYPE_MEDIMUM_CHANGER where using pscsi_create_type_other(), which does not call scsi_device_get() to take the device reference. Instead, rename pscsi_create_type_rom() to pscsi_create_type_nondisk() and use it for all cases.

Finally, also drop a dump_stack() in pscsi_get_blocks() for non TYPE_DISK, which in modern target-core can get invoked via target_sense_desc_format() during CHECK_CONDITION.

---
 drivers/target/target_core_pscsi.c |   47 +++++++++----------------------------
 1 file changed, 12 insertions(+), 35 deletions(-)

@@ -154,7 +154,7 @@ static void pscsi_tape_read_blocksize(st
 
 	buf = kzalloc(12, GFP_KERNEL);
 	if (!buf)
-		return;
+		goto out_free;
 
 	memset(cdb, 0, MAX_COMMAND_SIZE);
 	cdb[0] = MODE_SENSE;

@@ -169,9 +169,10 @@ static void pscsi_tape_read_blocksize(st
 	 * If MODE_SENSE still returns zero, set the default value to 1024.
 	 */
 	sdev->sector_size = (buf[9] << 16) | (buf[10] << 8) | (buf[11]);
+out_free:
 	if (!sdev->sector_size)
 		sdev->sector_size = 1024;
-out_free:
+
 	kfree(buf);
 }
 

@@ -314,9 +315,10 @@ static int pscsi_add_device_to_list(stru
 				sd->lun, sd->queue_depth);
 	}
 
-	dev->dev_attrib.hw_block_size = sd->sector_size;
+	dev->dev_attrib.hw_block_size =
+		min_not_zero((int)sd->sector_size, 512);
 	dev->dev_attrib.hw_max_sectors =
-		min_t(int, sd->host->max_sectors, queue_max_hw_sectors(q));
+		min_not_zero(sd->host->max_sectors, queue_max_hw_sectors(q));
 	dev->dev_attrib.hw_queue_depth = sd->queue_depth;
 
 	/*

@@ -339,8 +341,10 @@ static int pscsi_add_device_to_list(stru
 	/*
 	 * For TYPE_TAPE, attempt to determine blocksize with MODE_SENSE.
 	 */
-	if (sd->type == TYPE_TAPE)
+	if (sd->type == TYPE_TAPE) {
 		pscsi_tape_read_blocksize(dev, sd);
+		dev->dev_attrib.hw_block_size = sd->sector_size;
+	}
 	return 0;
 }
 

@@ -406,7 +410,7 @@ static int pscsi_create_type_disk(struct
 /*
  * Called with struct Scsi_Host->host_lock called.
  */
-static int pscsi_create_type_rom(struct se_device *dev, struct scsi_device *sd)
+static int pscsi_create_type_nondisk(struct se_device *dev, struct scsi_device *sd)
 	__releases(sh->host_lock)
 {
 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;

@@ -433,28 +437,6 @@ static int pscsi_create_type_rom(struct
 	return 0;
 }
 
-/*
- * Called with struct Scsi_Host->host_lock called.
- */
-static int pscsi_create_type_other(struct se_device *dev,
-		struct scsi_device *sd)
-	__releases(sh->host_lock)
-{
-	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
-	struct Scsi_Host *sh = sd->host;
-	int ret;
-
-	spin_unlock_irq(sh->host_lock);
-	ret = pscsi_add_device_to_list(dev, sd);
-	if (ret)
-		return ret;
-
-	pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%llu\n",
-		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
-		sd->channel, sd->id, sd->lun);
-	return 0;
-}
-
 static int pscsi_configure_device(struct se_device *dev)
 {
 	struct se_hba *hba = dev->se_hba;

@@ -542,11 +524,8 @@ static int pscsi_configure_device(struct
 		case TYPE_DISK:
 			ret = pscsi_create_type_disk(dev, sd);
 			break;
-		case TYPE_ROM:
-			ret = pscsi_create_type_rom(dev, sd);
-			break;
 		default:
-			ret = pscsi_create_type_other(dev, sd);
+			ret = pscsi_create_type_nondisk(dev, sd);
 			break;
 		}
 

@@ -611,8 +590,7 @@ static void pscsi_free_device(struct se_
 		else if (pdv->pdv_lld_host)
 			scsi_host_put(pdv->pdv_lld_host);
 
-		if ((sd->type == TYPE_DISK) || (sd->type == TYPE_ROM))
-			scsi_device_put(sd);
+		scsi_device_put(sd);
 
 		pdv->pdv_sd = NULL;
 	}

@@ -1069,7 +1047,6 @@ static sector_t pscsi_get_blocks(struct
 	if (pdv->pdv_bd && pdv->pdv_bd->bd_part)
 		return pdv->pdv_bd->bd_part->nr_sects;
 
-	dump_stack();
 	return 0;
 }
 

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

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

From: Anton Blanchard <[email protected]>

commit 85e8a23936ab3442de0c42da97d53b29f004ece1 upstream.

We see lpfc devices regularly fail during kexec. Fix this by adding a shutdown method which mirrors the remove method.

---
 drivers/scsi/lpfc/lpfc_init.c |    1 +
 1 file changed, 1 insertion(+)

@@ -11393,6 +11393,7 @@ static struct pci_driver lpfc_driver = {
 	.id_table	= lpfc_id_table,
 	.probe		= lpfc_pci_probe_one,
 	.remove		= lpfc_pci_remove_one,
+	.shutdown	= lpfc_pci_remove_one,
 	.suspend        = lpfc_pci_suspend_one,
 	.resume		= lpfc_pci_resume_one,
 	.err_handler    = &lpfc_err_handler,

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

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

From: John David Anglin <[email protected]>

commit 316ec0624f951166daedbe446988ef92ae72b59f upstream.

The previously submitted patch did not resolve the random segmentation faults observed on the phantom buildd system. There are still unresolved problems with the Debian 4.8 and 4.9 kernels on C8000.

The attached patch removes the flush of the offset map pages and does a whole data cache flush for large ranges. No other arch flushes the offset map in these routines as far as I can tell.

I have not observed any random segmentation faults on rp3440 in two weeks of testing with 4.10.0 and 4.10.1.

---
 arch/parisc/include/asm/cacheflush.h |   23 ++---------------------
 arch/parisc/kernel/cache.c           |   22 ++++++++++++++++++++++
 2 files changed, 24 insertions(+), 21 deletions(-)

@@ -45,28 +45,9 @@ static inline void flush_kernel_dcache_p
 
 #define flush_kernel_dcache_range(start,size) \
 	flush_kernel_dcache_range_asm((start), (start)+(size));
-/* vmap range flushes and invalidates.  Architecturally, we don't need
- * the invalidate, because the CPU should refuse to speculate once an
- * area has been flushed, so invalidate is left empty */
-static inline void flush_kernel_vmap_range(void *vaddr, int size)
-{
-	unsigned long start = (unsigned long)vaddr;
 
-	flush_kernel_dcache_range_asm(start, start + size);
-}
-static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
-{
-	unsigned long start = (unsigned long)vaddr;
-	void *cursor = vaddr;
-
-	for ( ; cursor < vaddr + size; cursor += PAGE_SIZE) {
-		struct page *page = vmalloc_to_page(cursor);
-
-		if (test_and_clear_bit(PG_dcache_dirty, &page->flags))
-			flush_kernel_dcache_page(page);
-	}
-	flush_kernel_dcache_range_asm(start, start + size);
-}
+void flush_kernel_vmap_range(void *vaddr, int size);
+void invalidate_kernel_vmap_range(void *vaddr, int size);
 
 #define flush_cache_vmap(start, end)		flush_cache_all()
 #define flush_cache_vunmap(start, end)		flush_cache_all()

@@ -633,3 +633,25 @@ flush_cache_page(struct vm_area_struct *
 		__flush_cache_page(vma, vmaddr, PFN_PHYS(pfn));
 	}
 }
+
+void flush_kernel_vmap_range(void *vaddr, int size)
+{
+	unsigned long start = (unsigned long)vaddr;
+
+	if ((unsigned long)size > parisc_cache_flush_threshold)
+		flush_data_cache();
+	else
+		flush_kernel_dcache_range_asm(start, start + size);
+}
+EXPORT_SYMBOL(flush_kernel_vmap_range);
+
+void invalidate_kernel_vmap_range(void *vaddr, int size)
+{
+	unsigned long start = (unsigned long)vaddr;
+
+	if ((unsigned long)size > parisc_cache_flush_threshold)
+		flush_data_cache();
+	else
+		flush_kernel_dcache_range_asm(start, start + size);
+}
+EXPORT_SYMBOL(invalidate_kernel_vmap_range);

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

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

From: Eric Anholt <[email protected]>

commit 3a62234680d86efa0239665ed8a0e908f1aef147 upstream.

The pm_runtime_put() we were using immediately released power on the device, which meant that we were generally turning the device off and on once per frame. In many profiles I've looked at, that added up to about 1% of CPU time, but this could get worse in the case of frequent rendering and readback (as may happen in X rendering). By keeping the device on until we've been idle for a couple of frames, we drop the overhead of runtime PM down to sub-.1%.

---
 drivers/gpu/drm/vc4/vc4_drv.c |    9 ++++++---
 drivers/gpu/drm/vc4/vc4_gem.c |    6 ++++--
 drivers/gpu/drm/vc4/vc4_v3d.c |    2 ++
 3 files changed, 12 insertions(+), 5 deletions(-)

@@ -61,21 +61,24 @@ static int vc4_get_param_ioctl(struct dr
 		if (ret < 0)
 			return ret;
 		args->value = V3D_READ(V3D_IDENT0);
-		pm_runtime_put(&vc4->v3d->pdev->dev);
+		pm_runtime_mark_last_busy(&vc4->v3d->pdev->dev);
+		pm_runtime_put_autosuspend(&vc4->v3d->pdev->dev);
 		break;
 	case DRM_VC4_PARAM_V3D_IDENT1:
 		ret = pm_runtime_get_sync(&vc4->v3d->pdev->dev);
 		if (ret < 0)
 			return ret;
 		args->value = V3D_READ(V3D_IDENT1);
-		pm_runtime_put(&vc4->v3d->pdev->dev);
+		pm_runtime_mark_last_busy(&vc4->v3d->pdev->dev);
+		pm_runtime_put_autosuspend(&vc4->v3d->pdev->dev);
 		break;
 	case DRM_VC4_PARAM_V3D_IDENT2:
 		ret = pm_runtime_get_sync(&vc4->v3d->pdev->dev);
 		if (ret < 0)
 			return ret;
 		args->value = V3D_READ(V3D_IDENT2);
-		pm_runtime_put(&vc4->v3d->pdev->dev);
+		pm_runtime_mark_last_busy(&vc4->v3d->pdev->dev);
+		pm_runtime_put_autosuspend(&vc4->v3d->pdev->dev);
 		break;
 	case DRM_VC4_PARAM_SUPPORTS_BRANCHES:
 		args->value = true;

@@ -711,8 +711,10 @@ vc4_complete_exec(struct drm_device *dev
 	}
 
 	mutex_lock(&vc4->power_lock);
-	if (--vc4->power_refcount == 0)
-		pm_runtime_put(&vc4->v3d->pdev->dev);
+	if (--vc4->power_refcount == 0) {
+		pm_runtime_mark_last_busy(&vc4->v3d->pdev->dev);
+		pm_runtime_put_autosuspend(&vc4->v3d->pdev->dev);
+	}
 	mutex_unlock(&vc4->power_lock);
 
 	kfree(exec);

@@ -222,6 +222,8 @@ static int vc4_v3d_bind(struct device *d
 		return ret;
 	}
 
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_set_autosuspend_delay(dev, 40); /* a little over 2 frames. */
 	pm_runtime_enable(dev);
 
 	return 0;

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

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

From: Peter Zijlstra <[email protected]>

commit e552a8389aa409e257b7dcba74f67f128f979ccc upstream.

Dmitry reported syzcaller tripped a use-after-free in perf_release().

After much puzzlement Oleg spotted the below scenario:

Task1 Task2

fork()

    perf_event_init_task()
    /* ... */
    goto bad_fork_$foo;
    /* ... */
    perf_event_free_task()
      mutex_lock(ctx->lock)
      perf_free_event(B)

                                  perf_event_release_kernel(A)
                                    mutex_lock(A->child_mutex)
                                    list_for_each_entry(child, ...) {
                                      /* child == B */
                                      ctx = B->ctx;
                                      get_ctx(ctx);
                                      mutex_unlock(A->child_mutex);

        mutex_lock(A->child_mutex)
        list_del_init(B->child_list)
        mutex_unlock(A->child_mutex)

        /* ... */

      mutex_unlock(ctx->lock);
      put_ctx() /* >0 */
    free_task();
                                      mutex_lock(ctx->lock);
                                      mutex_lock(A->child_mutex);
                                      /* ... */
                                      mutex_unlock(A->child_mutex);
                                      mutex_unlock(ctx->lock)
                                      put_ctx() /* 0 */
                                        ctx->task && !TOMBSTONE
                                          put_task_struct() /* UAF */

This patch closes the hole by making perf_event_free_task() destroy the task <-> ctx relation such that perf_event_release_kernel() will no longer observe the now dead task.

---
 kernel/events/core.c |   11 +++++++++++
 1 file changed, 11 insertions(+)

@@ -10333,6 +10333,17 @@ void perf_event_free_task(struct task_st
 			continue;
 
 		mutex_lock(&ctx->mutex);
+		raw_spin_lock_irq(&ctx->lock);
+		/*
+		 * Destroy the task <-> ctx relation and mark the context dead.
+		 *
+		 * This is important because even though the task hasn't been
+		 * exposed yet the context has been (through child_list).
+		 */
+		RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], NULL);
+		WRITE_ONCE(ctx->task, TASK_TOMBSTONE);
+		put_task_struct(task); /* cannot be last */
+		raw_spin_unlock_irq(&ctx->lock);
 again:
 		list_for_each_entry_safe(event, tmp, &ctx->pinned_groups,
 				group_entry)

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

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

From: Theodore Ts'o <[email protected]>

commit 2ba3e6e8afc9b6188b471f27cf2b5e3cf34e7af2 upstream.

It is OK for s_first_meta_bg to be equal to the number of block group descriptor blocks. (It rarely happens, but it shouldn't cause any problems.)

https://bugzilla.kernel.org/show_bug.cgi?id=194567

---
 fs/ext4/super.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -3830,7 +3830,7 @@ static int ext4_fill_super(struct super_
 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
 		   EXT4_DESC_PER_BLOCK(sb);
 	if (ext4_has_feature_meta_bg(sb)) {
-		if (le32_to_cpu(es->s_first_meta_bg) >= db_count) {
+		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
 			ext4_msg(sb, KERN_WARNING,
 				 "first meta block group too large: %u "
 				 "(group descriptor block count %u)",

This is the start of the stable review cycle for the 4.9.18 release. There are 24 patches in this series, all will be posted as a response to this one. If anyone has any issues with these being applied, please let me know.

Responses should be made by Sun Mar 26 15:12:08 UTC 2017. Anything received after that time might be too late.

The whole patch series can be found in one patch at:

	kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.9.18-rc1.gz

or in the git tree and branch at:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.9.y
and the diffstat can be found below.

thanks,

greg k-h

-------------
Pseudo-Shortlog of commits:

Greg Kroah-Hartman <[email protected]>

    Linux 4.9.18-rc1

Theodore Ts'o <[email protected]>
ext4: fix fencepost in s_first_meta_bg validation

Alex Deucher <[email protected]>
drm/amdgpu/si: add dpm quirk for Oland

Tejun Heo <[email protected]>
cgroup/pids: remove spurious suspicious RCU usage warning

Tahsin Erdogan <[email protected]>
percpu: acquire pcpu_lock when updating pcpu_nr_empty_pop_pages

Andreas Gruenbacher <[email protected]>
gfs2: Avoid alignment hole in struct lm_lockname

Johan Hovold <[email protected]>
isdn/gigaset: fix NULL-deref at probe

Max Lohrmann <[email protected]>
target: Fix VERIFY_16 handling in sbc_parse_cdb

Chris Leech <[email protected]>
scsi: libiscsi: add lock around task lists to fix list corruption regression

Anton Blanchard <[email protected]>
scsi: lpfc: Add shutdown method for kexec

Nicholas Bellinger <[email protected]>
target/pscsi: Fix TYPE_TAPE + TYPE_MEDIMUM_CHANGER export

Shaohua Li <[email protected]>
md/raid1/10: fix potential deadlock

Michael Ellerman <[email protected]>
powerpc/boot: Fix zImage TOC alignment

Rafael J. Wysocki <[email protected]>
cpufreq: Fix and clean up show_cpuinfo_cur_freq()

Olga Kornievskaia <[email protected]>
NFS prevent double free in async nfs4_exchange_id

Chuck Lever <[email protected]>
xprtrdma: Squelch kbuild sparse complaint

Peter Zijlstra <[email protected]>
perf/core: Fix event inheritance on fork()

Peter Zijlstra <[email protected]>
perf/core: Fix use-after-free in perf_release()

Helge Deller <[email protected]>
parisc: Fix system shutdown halt

John David Anglin <[email protected]>
parisc: Optimize flush_kernel_vmap_range and invalidate_kernel_vmap_range

Quinn Tran <[email protected]>
qla2xxx: Fix request queue corruption.

Quinn Tran <[email protected]>
qla2xxx: Fix memory leak for abts processing

Linus Torvalds <[email protected]>
give up on gcc ilog2() constant optimizations

Eric Anholt <[email protected]>
drm/vc4: Use runtime autosuspend to avoid thrashing V3D power state.

Eric Anholt <[email protected]>
drm/vc4: Fix termination of the initial scan for branch targets.

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

Diffstat:

 Makefile                                   |  4 +--
 arch/parisc/include/asm/cacheflush.h       | 23 ++-------------
 arch/parisc/kernel/cache.c                 | 22 ++++++++++++++
 arch/parisc/kernel/process.c               |  2 ++
 arch/powerpc/boot/zImage.lds.S             |  1 +
 drivers/cpufreq/cpufreq.c                  |  8 +++--
 drivers/gpu/drm/amd/amdgpu/si_dpm.c        |  6 ++++
 drivers/gpu/drm/vc4/vc4_drv.c              |  9 ++++--
 drivers/gpu/drm/vc4/vc4_gem.c              |  6 ++--
 drivers/gpu/drm/vc4/vc4_v3d.c              |  2 ++
 drivers/gpu/drm/vc4/vc4_validate_shaders.c | 19 +++++-------
 drivers/isdn/gigaset/bas-gigaset.c         |  3 ++
 drivers/md/raid10.c                        | 18 ++++++++++++
 drivers/scsi/libiscsi.c                    | 26 ++++++++++++++++-
 drivers/scsi/lpfc/lpfc_init.c              |  1 +
 drivers/scsi/qla2xxx/qla_target.c          | 14 +++++++--
 drivers/target/target_core_pscsi.c         | 47 ++++++++----------------------
 drivers/target/target_core_sbc.c           | 10 +++++--
 fs/ext4/super.c                            |  2 +-
 fs/gfs2/incore.h                           |  2 +-
 fs/nfs/nfs4proc.c                          |  9 +++---
 include/linux/log2.h                       | 13 ++-------
 include/scsi/libiscsi.h                    |  1 +
 kernel/cgroup_pids.c                       |  2 +-
 kernel/events/core.c                       | 16 ++++++++--
 mm/percpu.c                                |  5 +++-
 net/sunrpc/xprtrdma/verbs.c                |  3 +-
 tools/include/linux/log2.h                 | 13 ++-------
 28 files changed, 170 insertions(+), 117 deletions(-)

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

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

From: Johan Hovold <[email protected]>

commit 68c32f9c2a36d410aa242e661506e5b2c2764179 upstream.

Make sure to check the number of endpoints to avoid dereferencing a NULL-pointer should a malicious device lack endpoints.

---
 drivers/isdn/gigaset/bas-gigaset.c |    3 +++
 1 file changed, 3 insertions(+)

@@ -2317,6 +2317,9 @@ static int gigaset_probe(struct usb_inte
 		return -ENODEV;
 	}
 
+	if (hostif->desc.bNumEndpoints < 1)
+		return -ENODEV;
+
 	dev_info(&udev->dev,
 		 "%s: Device matched (Vendor: 0x%x, Product: 0x%x)\n",
 		 __func__, le16_to_cpu(udev->descriptor.idVendor),

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

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

From: Helge Deller <[email protected]>

commit 73580dac7618e4bcd21679f553cf3c97323fec46 upstream.

On those parisc machines which don't provide a software power off function, the system currently kills the init process at the end of a shutdown and unexpectedly restarts insteads of halting. Fix it by adding a loop which will not return.

---
 arch/parisc/kernel/process.c |    2 ++
 1 file changed, 2 insertions(+)

@@ -139,6 +139,8 @@ void machine_power_off(void)
 
 	printk(KERN_EMERG "System shut down completed.\n"
 	       "Please power this system off now.");
+
+	for (;;);
 }
 
 void (*pm_power_off)(void) = machine_power_off;

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

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

From: Tahsin Erdogan <[email protected]>

commit 320661b08dd6f1746d5c7ab4eb435ec64b97cd45 upstream.

Update to pcpu_nr_empty_pop_pages in pcpu_alloc() is currently done without holding pcpu_lock. This can lead to bad updates to the variable. Add missing lock calls.

---
 mm/percpu.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

@@ -1010,8 +1010,11 @@ area_found:
 		mutex_unlock(&pcpu_alloc_mutex);
 	}
 
-	if (chunk != pcpu_reserved_chunk)
+	if (chunk != pcpu_reserved_chunk) {
+		spin_lock_irqsave(&pcpu_lock, flags);
 		pcpu_nr_empty_pop_pages -= occ_pages;
+		spin_unlock_irqrestore(&pcpu_lock, flags);
+	}
 
 	if (pcpu_nr_empty_pop_pages < PCPU_EMPTY_POP_PAGES_LOW)
 		pcpu_schedule_balance_work();

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

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

From: Quinn Tran <[email protected]>

commit ae940f2c472a62904dc18234de5cf3ed28f195ee upstream.

---
 drivers/scsi/qla2xxx/qla_target.c |    2 ++
 1 file changed, 2 insertions(+)

@@ -6794,6 +6794,8 @@ qlt_handle_abts_recv_work(struct work_st
 	spin_lock_irqsave(&ha->hardware_lock, flags);
 	qlt_response_pkt_all_vps(vha, (response_t *)&op->atio);
 	spin_unlock_irqrestore(&ha->hardware_lock, flags);
+
+	kfree(op);
 }
 
 void

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

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

From: Peter Zijlstra <[email protected]>

commit e7cc4865f0f31698ef2f7aac01a50e78968985b7 upstream.

While hunting for clues to a use-after-free, Oleg spotted that perf_event_init_context() can loose an error value with the result that fork() can succeed even though we did not fully inherit the perf event context.

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

@@ -10597,7 +10597,7 @@ static int perf_event_init_context(struc
 		ret = inherit_task_group(event, parent, parent_ctx,
 					 child, ctxn, &inherited_all);
 		if (ret)
-			break;
+			goto out_unlock;
 	}
 
 	/*

@@ -10613,7 +10613,7 @@ static int perf_event_init_context(struc
 		ret = inherit_task_group(event, parent, parent_ctx,
 					 child, ctxn, &inherited_all);
 		if (ret)
-			break;
+			goto out_unlock;
 	}
 
 	raw_spin_lock_irqsave(&parent_ctx->lock, flags);

@@ -10641,6 +10641,7 @@ static int perf_event_init_context(struc
 	}
 
 	raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
+out_unlock:
 	mutex_unlock(&parent_ctx->mutex);
 
 	perf_unpin_context(parent_ctx);

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

thanks,
-- Shuah

Hello Kevin,

This seems to be the bug that's fixed by commit f0a8b49c03d2 ("drm/bridge:
analogix dp: Fix runtime PM state on driver bind") [0]. I thought it was only a regression for v4.10, but it looks like that also affects v4.9.

[0]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f0a8b49c03d2

Best regards,

Javier Martinez Canillas
Open Source Group
Samsung Research America

Build results:

	total: 149 pass: 149 fail: 0
Qemu test results:
	total: 122 pass: 122 fail: 0

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

Guenter

Hi Javier,

Thanks for checking.

Do you plan to request a backport to stable v4.9 also?

Thanks,

Kevin

Hello Kevin,

Yes, I'll try to reproduce it today, test if the mentioned commit fixes and if that's the case request a backport for v4.9 stable.

Best regards,

Javier Martinez Canillas
Open Source Group
Samsung Research America