5.6.2-rc1 review

This is the start of the stable review cycle for the 5.6.2 release. There are 10 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 Fri, 03 Apr 2020 16:09:36 +0000. Anything received after that time might be too late.

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

	https://www.kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.6.2-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-5.6.y
and the diffstat can be found below.

thanks,

greg k-h

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

Greg Kroah-Hartman <[email protected]>

    Linux 5.6.2-rc1

Georg Müller <[email protected]>
platform/x86: pmc_atom: Add Lex 2I385SW to critclk_systems DMI table

Eric Biggers <[email protected]>
vt: vt_ioctl: fix use-after-free in vt_in_use()

Eric Biggers <[email protected]>
vt: vt_ioctl: fix VT_DISALLOCATE freeing in-use virtual console

Eric Biggers <[email protected]>
vt: vt_ioctl: remove unnecessary console allocation checks

Jiri Slaby <[email protected]>
vt: switch vt_dont_switch to bool

Jiri Slaby <[email protected]>
vt: ioctl, switch VT_IS_IN_USE and VT_BUSY to inlines

Jiri Slaby <[email protected]>
vt: selection, introduce vc_is_sel

Lanqing Liu <[email protected]>
serial: sprd: Fix a dereference warning

Johannes Berg <[email protected]>
mac80211: fix authentication with iwlwifi/mvm

Daniel Borkmann <[email protected]>
bpf: update jmp32 test cases to fix range bound deduction

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

Diffstat:

 Makefile                                     |  4 +-
 drivers/platform/x86/pmc_atom.c              |  8 +++
 drivers/tty/serial/sprd_serial.c             |  3 +-
 drivers/tty/vt/selection.c                   |  5 ++
 drivers/tty/vt/vt.c                          | 30 +++++++++--
 drivers/tty/vt/vt_ioctl.c                    | 75 +++++++++++++++-------------
 include/linux/selection.h                    |  4 +-
 include/linux/vt_kern.h                      |  2 +-
 net/mac80211/tx.c                            |  3 +-
 tools/testing/selftests/bpf/verifier/jmp32.c |  9 ++--
 10 files changed, 94 insertions(+), 49 deletions(-)

From: Daniel Borkmann <[email protected]>

[ no upstream commit ]

Since commit f2d67fec0b43 ("bpf: Undo incorrect __reg_bound_offset32 handling") has been backported to stable, we also need to update related test cases that started to (expectedly) fail on stable. Given the functionality has been reverted we need to move the result to REJECT.

---
 tools/testing/selftests/bpf/verifier/jmp32.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

@@ -783,7 +783,8 @@
 	},
 	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
 	.fixup_map_hash_48b = { 4 },
-	.result = ACCEPT,
+	.result = REJECT,
+	.errstr = "R8 unbounded memory access",
 	.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
 },
 {

@@ -811,7 +812,8 @@
 	},
 	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
 	.fixup_map_hash_48b = { 4 },
-	.result = ACCEPT,
+	.result = REJECT,
+	.errstr = "R8 unbounded memory access",
 	.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
 },
 {

@@ -839,6 +841,7 @@
 	},
 	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
 	.fixup_map_hash_48b = { 4 },
-	.result = ACCEPT,
+	.result = REJECT,
+	.errstr = "R8 unbounded memory access",
 	.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
 },

From: Johannes Berg <[email protected]>

commit be8c827f50a0bcd56361b31ada11dc0a3c2fd240 upstream.

The original patch didn't copy the ieee80211_is_data() condition because on most drivers the management frames don't go through this path. However, they do on iwlwifi/mvm, so we do need to keep the condition here.

---
 net/mac80211/tx.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -3610,7 +3610,8 @@ begin:
 		 * Drop unicast frames to unauthorised stations unless they are
 		 * EAPOL frames from the local station.
 		 */
-		if (unlikely(!ieee80211_vif_is_mesh(&tx.sdata->vif) &&
+		if (unlikely(ieee80211_is_data(hdr->frame_control) &&
+			     !ieee80211_vif_is_mesh(&tx.sdata->vif) &&
 			     tx.sdata->vif.type != NL80211_IFTYPE_OCB &&
 			     !is_multicast_ether_addr(hdr->addr1) &&
 			     !test_sta_flag(tx.sta, WLAN_STA_AUTHORIZED) &&

From: Lanqing Liu <[email protected]>

commit efc176929a3505a30c3993ddd393b40893649bd2 upstream.

We should validate if the 'sup' is NULL or not before freeing DMA memory, to fix below warning.

"drivers/tty/serial/sprd_serial.c:1141 sprd_remove()
error: we previously assumed 'sup' could be null (see line 1132)"

---
 drivers/tty/serial/sprd_serial.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

@@ -1132,14 +1132,13 @@ static int sprd_remove(struct platform_d
 	if (sup) {
 		uart_remove_one_port(&sprd_uart_driver, &sup->port);
 		sprd_port[sup->port.line] = NULL;
+		sprd_rx_free_buf(sup);
 		sprd_ports_num--;
 	}
 
 	if (!sprd_ports_num)
 		uart_unregister_driver(&sprd_uart_driver);
 
-	sprd_rx_free_buf(sup);
-
 	return 0;
 }
 

From: Jiri Slaby <[email protected]>

commit dce05aa6eec977f1472abed95ccd71276b9a3864 upstream.

Avoid global variables (namely sel_cons) by introducing vc_is_sel. It checks whether the parameter is the current selection console. This will help putting sel_cons to a struct later.

---
 drivers/tty/vt/selection.c |    5 +++++
 drivers/tty/vt/vt.c        |    7 ++++---
 drivers/tty/vt/vt_ioctl.c  |    2 +-
 include/linux/selection.h  |    4 +++-
 4 files changed, 13 insertions(+), 5 deletions(-)

@@ -88,6 +88,11 @@ void clear_selection(void)
 }
 EXPORT_SYMBOL_GPL(clear_selection);
 
+bool vc_is_sel(struct vc_data *vc)
+{
+	return vc == sel_cons;
+}
+
 /*
  * User settable table: what characters are to be considered alphabetic?
  * 128 bits. Locked by the console lock.

@@ -890,8 +890,9 @@ static void hide_softcursor(struct vc_da
 
 static void hide_cursor(struct vc_data *vc)
 {
-	if (vc == sel_cons)
+	if (vc_is_sel(vc))
 		clear_selection();
+
 	vc->vc_sw->con_cursor(vc, CM_ERASE);
 	hide_softcursor(vc);
 }

@@ -901,7 +902,7 @@ static void set_cursor(struct vc_data *v
 	if (!con_is_fg(vc) || console_blanked || vc->vc_mode == KD_GRAPHICS)
 		return;
 	if (vc->vc_deccm) {
-		if (vc == sel_cons)
+		if (vc_is_sel(vc))
 			clear_selection();
 		add_softcursor(vc);
 		if ((vc->vc_cursor_type & 0x0f) != 1)

@@ -1207,7 +1208,7 @@ static int vc_do_resize(struct tty_struc
 		}
 	}
 
-	if (vc == sel_cons)
+	if (vc_is_sel(vc))
 		clear_selection();
 
 	old_rows = vc->vc_rows;

@@ -43,7 +43,7 @@ char vt_dont_switch;
 extern struct tty_driver *console_driver;
 
 #define VT_IS_IN_USE(i)	(console_driver->ttys[i] && console_driver->ttys[i]->count)
-#define VT_BUSY(i)	(VT_IS_IN_USE(i) || i == fg_console || vc_cons[i].d == sel_cons)
+#define VT_BUSY(i)	(VT_IS_IN_USE(i) || i == fg_console || vc_is_sel(vc_cons[i].d))
 
 /*
  * Console (vt and kd) routines, as defined by USL SVR4 manual, and by

@@ -11,8 +11,8 @@
 #include <linux/tiocl.h>
 #include <linux/vt_buffer.h>
 
-extern struct vc_data *sel_cons;
 struct tty_struct;
+struct vc_data;
 
 extern void clear_selection(void);
 extern int set_selection_user(const struct tiocl_selection __user *sel,

@@ -24,6 +24,8 @@ extern int sel_loadlut(char __user *p);
 extern int mouse_reporting(void);
 extern void mouse_report(struct tty_struct * tty, int butt, int mrx, int mry);
 
+bool vc_is_sel(struct vc_data *vc);
+
 extern int console_blanked;
 
 extern const unsigned char color_table[];

From: Jiri Slaby <[email protected]>

commit e587e8f17433ddb26954f0edf5b2f95c42155ae9 upstream.

These two were macros. Switch them to static inlines, so that it's more understandable what they are doing.

---
 drivers/tty/vt/vt_ioctl.c |   29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

@@ -40,10 +40,25 @@
 #include <linux/selection.h>
 
 char vt_dont_switch;
-extern struct tty_driver *console_driver;
 
-#define VT_IS_IN_USE(i)	(console_driver->ttys[i] && console_driver->ttys[i]->count)
-#define VT_BUSY(i)	(VT_IS_IN_USE(i) || i == fg_console || vc_is_sel(vc_cons[i].d))
+static inline bool vt_in_use(unsigned int i)
+{
+	extern struct tty_driver *console_driver;
+
+	return console_driver->ttys[i] && console_driver->ttys[i]->count;
+}
+
+static inline bool vt_busy(int i)
+{
+	if (vt_in_use(i))
+		return true;
+	if (i == fg_console)
+		return true;
+	if (vc_is_sel(vc_cons[i].d))
+		return true;
+
+	return false;
+}
 
 /*
  * Console (vt and kd) routines, as defined by USL SVR4 manual, and by

@@ -289,7 +304,7 @@ static int vt_disallocate(unsigned int v
 	int ret = 0;
 
 	console_lock();
-	if (VT_BUSY(vc_num))
+	if (vt_busy(vc_num))
 		ret = -EBUSY;
 	else if (vc_num)
 		vc = vc_deallocate(vc_num);

@@ -311,7 +326,7 @@ static void vt_disallocate_all(void)
 
 	console_lock();
 	for (i = 1; i < MAX_NR_CONSOLES; i++)
-		if (!VT_BUSY(i))
+		if (!vt_busy(i))
 			vc[i] = vc_deallocate(i);
 		else
 			vc[i] = NULL;

@@ -648,7 +663,7 @@ int vt_ioctl(struct tty_struct *tty,
 			state = 1;	/* /dev/tty0 is always open */
 			for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
 							++i, mask <<= 1)
-				if (VT_IS_IN_USE(i))
+				if (vt_in_use(i))
 					state |= mask;
 			ret = put_user(state, &vtstat->v_state);
 		}

@@ -661,7 +676,7 @@ int vt_ioctl(struct tty_struct *tty,
 	case VT_OPENQRY:
 		/* FIXME: locking ? - but then this is a stupid API */
 		for (i = 0; i < MAX_NR_CONSOLES; ++i)
-			if (! VT_IS_IN_USE(i))
+			if (!vt_in_use(i))
 				break;
 		uival = i < MAX_NR_CONSOLES ? (i+1) : -1;
 		goto setint;		 

From: Jiri Slaby <[email protected]>

commit f400991bf872debffb01c46da882dc97d7e3248e upstream.

vt_dont_switch is pure boolean, no need for whole char.

---
 drivers/tty/vt/vt_ioctl.c |    6 +++---
 include/linux/vt_kern.h   |    2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

@@ -39,7 +39,7 @@
 #include <linux/kbd_diacr.h>
 #include <linux/selection.h>
 
-char vt_dont_switch;
+bool vt_dont_switch;
 
 static inline bool vt_in_use(unsigned int i)
 {

@@ -1026,12 +1026,12 @@ int vt_ioctl(struct tty_struct *tty,
 	case VT_LOCKSWITCH:
 		if (!capable(CAP_SYS_TTY_CONFIG))
 			return -EPERM;
-		vt_dont_switch = 1;
+		vt_dont_switch = true;
 		break;
 	case VT_UNLOCKSWITCH:
 		if (!capable(CAP_SYS_TTY_CONFIG))
 			return -EPERM;
-		vt_dont_switch = 0;
+		vt_dont_switch = false;
 		break;
 	case VT_GETHIFONTMASK:
 		ret = put_user(vc->vc_hi_font_mask,

@@ -135,7 +135,7 @@ extern int do_unbind_con_driver(const st
 			     int deflt);
 int vty_init(const struct file_operations *console_fops);
 
-extern char vt_dont_switch;
+extern bool vt_dont_switch;
 extern int default_utf8;
 extern int global_cursor_default;
 

From: Eric Biggers <[email protected]>

commit 1aa6e058dd6cd04471b1f21298270014daf48ac9 upstream.

The vc_cons_allocated() checks in vt_ioctl() and vt_compat_ioctl() are unnecessary because they can only be reached by calling ioctl() on an open tty, which implies the corresponding virtual console is allocated.

And even if the virtual console *could* be freed concurrently, then these checks would be broken since they aren't done under console_lock, and the vc_data is dereferenced before them anyway.

So, remove these unneeded checks to avoid confusion.

---
 drivers/tty/vt/vt_ioctl.c |   16 +---------------
 1 file changed, 1 insertion(+), 15 deletions(-)

@@ -350,22 +350,13 @@ int vt_ioctl(struct tty_struct *tty,
 {
 	struct vc_data *vc = tty->driver_data;
 	struct console_font_op op;	/* used in multiple places here */
-	unsigned int console;
+	unsigned int console = vc->vc_num;
 	unsigned char ucval;
 	unsigned int uival;
 	void __user *up = (void __user *)arg;
 	int i, perm;
 	int ret = 0;
 
-	console = vc->vc_num;
-
-
-	if (!vc_cons_allocated(console)) { 	/* impossible? */
-		ret = -ENOIOCTLCMD;
-		goto out;
-	}
-
-
 	/*
 	 * To have permissions to do most of the vt ioctls, we either have
 	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.

@@ -1195,14 +1186,9 @@ long vt_compat_ioctl(struct tty_struct *
 {
 	struct vc_data *vc = tty->driver_data;
 	struct console_font_op op;	/* used in multiple places here */
-	unsigned int console = vc->vc_num;
 	void __user *up = compat_ptr(arg);
 	int perm;
 
-
-	if (!vc_cons_allocated(console)) 	/* impossible? */
-		return -ENOIOCTLCMD;
-
 	/*
 	 * To have permissions to do most of the vt ioctls, we either have
 	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.

From: Eric Biggers <[email protected]>

commit ca4463bf8438b403596edd0ec961ca0d4fbe0220 upstream.

The VT_DISALLOCATE ioctl can free a virtual console while tty_release() is still running, causing a use-after-free in con_shutdown(). This occurs because VT_DISALLOCATE considers a virtual console's 'struct vc_data' to be unused as soon as the corresponding tty's refcount hits 0. But actually it may be still being closed.

Fix this by making vc_data be reference-counted via the embedded 'struct tty_port'. A newly allocated virtual console has refcount 1. Opening it for the first time increments the refcount to 2. Closing it for the last time decrements the refcount (in tty_operations::cleanup() so that it happens late enough), as does VT_DISALLOCATE.

Reproducer:

	#include <fcntl.h>
	#include <linux/vt.h>
	#include <sys/ioctl.h>
	#include <unistd.h>

	int main()
	{
		if (fork()) {
			for (;;)
				close(open("/dev/tty5", O_RDWR));
		} else {
			int fd = open("/dev/tty10", O_RDWR);

			for (;;)
				ioctl(fd, VT_DISALLOCATE, 5);
		}
	}

KASAN report:

	BUG: KASAN: use-after-free in con_shutdown+0x76/0x80 drivers/tty/vt/vt.c:3278
	Write of size 8 at addr ffff88806a4ec108 by task syz_vt/129

	CPU: 0 PID: 129 Comm: syz_vt Not tainted 5.6.0-rc2 #11
	Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20191223_100556-anatol 04/01/2014
	Call Trace:
	 [...]
	 con_shutdown+0x76/0x80 drivers/tty/vt/vt.c:3278
	 release_tty+0xa8/0x410 drivers/tty/tty_io.c:1514
	 tty_release_struct+0x34/0x50 drivers/tty/tty_io.c:1629
	 tty_release+0x984/0xed0 drivers/tty/tty_io.c:1789
	 [...]

	Allocated by task 129:
	 [...]
	 kzalloc include/linux/slab.h:669 [inline]
	 vc_allocate drivers/tty/vt/vt.c:1085 [inline]
	 vc_allocate+0x1ac/0x680 drivers/tty/vt/vt.c:1066
	 con_install+0x4d/0x3f0 drivers/tty/vt/vt.c:3229
	 tty_driver_install_tty drivers/tty/tty_io.c:1228 [inline]
	 tty_init_dev+0x94/0x350 drivers/tty/tty_io.c:1341
	 tty_open_by_driver drivers/tty/tty_io.c:1987 [inline]
	 tty_open+0x3ca/0xb30 drivers/tty/tty_io.c:2035
	 [...]

	Freed by task 130:
	 [...]
	 kfree+0xbf/0x1e0 mm/slab.c:3757
	 vt_disallocate drivers/tty/vt/vt_ioctl.c:300 [inline]
	 vt_ioctl+0x16dc/0x1e30 drivers/tty/vt/vt_ioctl.c:818
	 tty_ioctl+0x9db/0x11b0 drivers/tty/tty_io.c:2660
	 [...]

---
 drivers/tty/vt/vt.c       |   23 ++++++++++++++++++++++-
 drivers/tty/vt/vt_ioctl.c |   12 ++++--------
 2 files changed, 26 insertions(+), 9 deletions(-)

@@ -1075,6 +1075,17 @@ static void visual_deinit(struct vc_data
 	module_put(vc->vc_sw->owner);
 }
 
+static void vc_port_destruct(struct tty_port *port)
+{
+	struct vc_data *vc = container_of(port, struct vc_data, port);
+
+	kfree(vc);
+}
+
+static const struct tty_port_operations vc_port_ops = {
+	.destruct = vc_port_destruct,
+};
+
 int vc_allocate(unsigned int currcons)	/* return 0 on success */
 {
 	struct vt_notifier_param param;

@@ -1100,6 +1111,7 @@ int vc_allocate(unsigned int currcons)	/
 
 	vc_cons[currcons].d = vc;
 	tty_port_init(&vc->port);
+	vc->port.ops = &vc_port_ops;
 	INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
 
 	visual_init(vc, currcons, 1);

@@ -3254,6 +3266,7 @@ static int con_install(struct tty_driver
 
 	tty->driver_data = vc;
 	vc->port.tty = tty;
+	tty_port_get(&vc->port);
 
 	if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
 		tty->winsize.ws_row = vc_cons[currcons].d->vc_rows;

@@ -3289,6 +3302,13 @@ static void con_shutdown(struct tty_stru
 	console_unlock();
 }
 
+static void con_cleanup(struct tty_struct *tty)
+{
+	struct vc_data *vc = tty->driver_data;
+
+	tty_port_put(&vc->port);
+}
+
 static int default_color           = 7; /* white */
 static int default_italic_color    = 2; // green (ASCII)
 static int default_underline_color = 3; // cyan (ASCII)

@@ -3414,7 +3434,8 @@ static const struct tty_operations con_o
 	.throttle = con_throttle,
 	.unthrottle = con_unthrottle,
 	.resize = vt_resize,
-	.shutdown = con_shutdown
+	.shutdown = con_shutdown,
+	.cleanup = con_cleanup,
 };
 
 static struct cdev vc0_cdev;

@@ -310,10 +310,8 @@ static int vt_disallocate(unsigned int v
 		vc = vc_deallocate(vc_num);
 	console_unlock();
 
-	if (vc && vc_num >= MIN_NR_CONSOLES) {
-		tty_port_destroy(&vc->port);
-		kfree(vc);
-	}
+	if (vc && vc_num >= MIN_NR_CONSOLES)
+		tty_port_put(&vc->port);
 
 	return ret;
 }

@@ -333,10 +331,8 @@ static void vt_disallocate_all(void)
 	console_unlock();
 
 	for (i = 1; i < MAX_NR_CONSOLES; i++) {
-		if (vc[i] && i >= MIN_NR_CONSOLES) {
-			tty_port_destroy(&vc[i]->port);
-			kfree(vc[i]);
-		}
+		if (vc[i] && i >= MIN_NR_CONSOLES)
+			tty_port_put(&vc[i]->port);
 	}
 }
 

From: Eric Biggers <[email protected]>

commit 7cf64b18b0b96e751178b8d0505d8466ff5a448f upstream.

vt_in_use() dereferences console_driver->ttys[i] without proper locking. This is broken because the tty can be closed and freed concurrently.

We could fix this by using 'READ_ONCE(console_driver->ttys[i]) != NULL' and skipping the check of tty_struct::count. But, looking at console_driver->ttys[i] isn't really appropriate anyway because even if it is NULL the tty can still be in the process of being closed.

Instead, fix it by making vt_in_use() require console_lock() and check whether the vt is allocated and has port refcount > 1. This works since following the patch "vt: vt_ioctl: fix VT_DISALLOCATE freeing in-use virtual console" the port refcount is incremented while the vt is open.

Reproducer (very unreliable, but it worked for me after a few minutes):

	#include <fcntl.h>
	#include <linux/vt.h>

	int main()
	{
		int fd, nproc;
		struct vt_stat state;
		char ttyname[16];

		fd = open("/dev/tty10", O_RDONLY);
		for (nproc = 1; nproc < 8; nproc *= 2)
			fork();
		for (;;) {
			sprintf(ttyname, "/dev/tty%d", rand() % 8);
			close(open(ttyname, O_RDONLY));
			ioctl(fd, VT_GETSTATE, &state);
		}
	}

KASAN report:

	BUG: KASAN: use-after-free in vt_in_use drivers/tty/vt/vt_ioctl.c:48 [inline]
	BUG: KASAN: use-after-free in vt_ioctl+0x1ad3/0x1d70 drivers/tty/vt/vt_ioctl.c:657
	Read of size 4 at addr ffff888065722468 by task syz-vt2/132

	CPU: 0 PID: 132 Comm: syz-vt2 Not tainted 5.6.0-rc5-00130-g089b6d3654916 #13
	Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20191223_100556-anatol 04/01/2014
	Call Trace:
	 [...]
	 vt_in_use drivers/tty/vt/vt_ioctl.c:48 [inline]
	 vt_ioctl+0x1ad3/0x1d70 drivers/tty/vt/vt_ioctl.c:657
	 tty_ioctl+0x9db/0x11b0 drivers/tty/tty_io.c:2660
	 [...]

	Allocated by task 136:
	 [...]
	 kzalloc include/linux/slab.h:669 [inline]
	 alloc_tty_struct+0x96/0x8a0 drivers/tty/tty_io.c:2982
	 tty_init_dev+0x23/0x350 drivers/tty/tty_io.c:1334
	 tty_open_by_driver drivers/tty/tty_io.c:1987 [inline]
	 tty_open+0x3ca/0xb30 drivers/tty/tty_io.c:2035
	 [...]

	Freed by task 41:
	 [...]
	 kfree+0xbf/0x200 mm/slab.c:3757
	 free_tty_struct+0x8d/0xb0 drivers/tty/tty_io.c:177
	 release_one_tty+0x22d/0x2f0 drivers/tty/tty_io.c:1468
	 process_one_work+0x7f1/0x14b0 kernel/workqueue.c:2264
	 worker_thread+0x8b/0xc80 kernel/workqueue.c:2410
	 [...]

---
 drivers/tty/vt/vt_ioctl.c |   16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

@@ -43,9 +43,15 @@ bool vt_dont_switch;
 
 static inline bool vt_in_use(unsigned int i)
 {
-	extern struct tty_driver *console_driver;
+	const struct vc_data *vc = vc_cons[i].d;
 
-	return console_driver->ttys[i] && console_driver->ttys[i]->count;
+	/*
+	 * console_lock must be held to prevent the vc from being deallocated
+	 * while we're checking whether it's in-use.
+	 */
+	WARN_CONSOLE_UNLOCKED();
+
+	return vc && kref_read(&vc->port.kref) > 1;
 }
 
 static inline bool vt_busy(int i)

@@ -643,15 +649,16 @@ int vt_ioctl(struct tty_struct *tty,
 		struct vt_stat __user *vtstat = up;
 		unsigned short state, mask;
 
-		/* Review: FIXME: Console lock ? */
 		if (put_user(fg_console + 1, &vtstat->v_active))
 			ret = -EFAULT;
 		else {
 			state = 1;	/* /dev/tty0 is always open */
+			console_lock(); /* required by vt_in_use() */
 			for (i = 0, mask = 2; i < MAX_NR_CONSOLES && mask;
 							++i, mask <<= 1)
 				if (vt_in_use(i))
 					state |= mask;
+			console_unlock();
 			ret = put_user(state, &vtstat->v_state);
 		}
 		break;

@@ -661,10 +668,11 @@ int vt_ioctl(struct tty_struct *tty,
 	 * Returns the first available (non-opened) console.
 	 */
 	case VT_OPENQRY:
-		/* FIXME: locking ? - but then this is a stupid API */
+		console_lock(); /* required by vt_in_use() */
 		for (i = 0; i < MAX_NR_CONSOLES; ++i)
 			if (!vt_in_use(i))
 				break;
+		console_unlock();
 		uival = i < MAX_NR_CONSOLES ? (i+1) : -1;
 		goto setint;		 
 

From: Georg Müller <[email protected]>

commit 95b31e35239e5e1689e3d965d692a313c71bd8ab upstream.

The Lex 2I385SW board has two Intel I211 ethernet controllers. Without this patch, only the first port is usable. The second port fails to start with the following message:

    igb: probe of 0000:02:00.0 failed with error -2

---
 drivers/platform/x86/pmc_atom.c |    8 ++++++++
 1 file changed, 8 insertions(+)

@@ -385,6 +385,14 @@ static const struct dmi_system_id critcl
 	},
 	{
 		/* pmc_plt_clk* - are used for ethernet controllers */
+		.ident = "Lex 2I385SW",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Lex BayTrail"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "2I385SW"),
+		},
+	},
+	{
+		/* pmc_plt_clk* - are used for ethernet controllers */
 		.ident = "Beckhoff CB3163",
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "Beckhoff Automation"),

Good. You made 5.6.1 so quickly that I didn't have time to react and say that it makes little sense without the 802.11 fix, but you're obviously making 5.6.2 quickly, so..

That was just horrible timing. David's email to say "holup" came in literally _one_ minute after I had sent the 5.6 announcement: my timestamps for that unfortunate thing is "3:51 PM" for my 5.6 announcement, and the email where David says "Meanwhile, we have a wireless regression, and I'll get the fix for that to you by the end of today" has a timestamp of "3:52 PM"

(Ok, so me actually tagging the tree and pushing it out happened about half an hour earlier, so it's not like it was quite that close, but I found the timing of the almost-crossed emails to be funny/sad).

Linus

Yeah, 5.6.1 had to go out fast, sorry I missed this patch. Luckily it seems that every distro vendor heard about it (or asked me about it) already, and have included it in their trees so the majority of users shouldn't hit this just yet.

And, if this passes Guenter's test builds quickly (hint), I can push it out quickly as well :)

thanks,

greg k-h

Running ... but you submitted 7 branches all in one go, so it will take a while to complete. Results should be available sometime early in the evening (PDT).

Guenter

wifi issue I was seeing on my laptop with 5.6.0 is now resolved. Thanks for pulling this in quickly.

thanks,
-- Shuah

Build results:

	total: 155 pass: 155 fail: 0
Qemu test results:
	total: 428 pass: 428 fail: 0

Guenter

Wonderful, thanks for testing all of these and letting me know.

greg k-h

All tests are passing for Tegra ...

Test results for stable-v5.6:

    13 builds:	13 pass, 0 fail
    24 boots:	24 pass, 0 fail
    40 tests:	40 pass, 0 fail

Linux version: 5.6.2-rc1-g6c8d51f98078
Boards tested: tegra124-jetson-tk1, tegra186-p2771-0000,

                tegra194-p2972-0000, tegra20-ventana,
                tegra210-p2371-2180, tegra210-p3450-0000,
                tegra30-cardhu-a04

Cheers
Jon

nvpublic

Great, thanks for testing all of these and letting me know.

greg k-h

Results from Linaro’s test farm.
No regressions on arm64, arm, x86_64, and i386.

Summary
------------------------------------------------------------------------

kernel: 5.6.2-rc1
git repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
git branch: linux-5.6.y
git commit: 6c8d51f98078987586685d72fd3d66b88f3f965a
git describe: v5.6.1-11-g6c8d51f98078
Test details: https://qa-reports.linaro.org/lkft/linux-stable-rc-5.6-oe/build/v5.6.1-11-g6c8d51f98078

No regressions (compared to build v5.6.1)

No fixes (compared to build v5.6.1)

Ran 18887 total tests in the following environments and test suites.

Environments
--------------
- dragonboard-410c
- hi6220-hikey
- i386
- juno-r2
- juno-r2-compat
- juno-r2-kasan
- nxp-ls2088
- x15
- x86
- x86-kasan

Test Suites
-----------
* build
* install-android-platform-tools-r2800
* libhugetlbfs
* linux-log-parser
* ltp-cap_bounds-tests
* ltp-commands-tests
* ltp-containers-tests
* ltp-cpuhotplug-tests
* ltp-crypto-tests
* ltp-cve-tests
* ltp-fcntl-locktests-tests
* ltp-filecaps-tests
* ltp-fs-tests
* ltp-fs_bind-tests
* ltp-fs_perms_simple-tests
* ltp-fsx-tests
* ltp-hugetlb-tests
* ltp-math-tests
* ltp-mm-tests
* ltp-nptl-tests
* ltp-pty-tests
* ltp-securebits-tests
* ltp-syscalls-tests
* v4l2-compliance
* ltp-ipc-tests
* kvm-unit-tests
* ltp-dio-tests
* ltp-io-tests
* ltp-open-posix-tests
* ltp-sched-tests

Linaro LKFT
https://lkft.linaro.org

Great, thanks for testing all of tehse and letting me know.

greg k-h