<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers, branch v5.4.30</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>clk: ti: am43xx: Fix clock parent for RTC clock</title>
<updated>2020-04-02T13:11:02+00:00</updated>
<author>
<name>Tony Lindgren</name>
<email>tony@atomide.com</email>
</author>
<published>2020-02-21T17:10:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=61bbc823a17abb3798568cfb11ff38fc22317442'/>
<id>61bbc823a17abb3798568cfb11ff38fc22317442</id>
<content type='text'>
commit 5f3d9b07b9bb4679922f0b2e2baa770e74a6bbd3 upstream.

Currently enabling clkctrl clock on am4 can fail for RTC as the clock
parent is wrong for RTC.

Fixes: 76a1049b84dd ("clk: ti: am43xx: add new clkctrl data for am43xx")
Signed-off-by: Tony Lindgren &lt;tony@atomide.com&gt;
Link: https://lkml.kernel.org/r/20200221171030.39326-1-tony@atomide.com
Acked-by: Tero Kristo &lt;t-kristo@ti.com&gt;
Signed-off-by: Stephen Boyd &lt;sboyd@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 5f3d9b07b9bb4679922f0b2e2baa770e74a6bbd3 upstream.

Currently enabling clkctrl clock on am4 can fail for RTC as the clock
parent is wrong for RTC.

Fixes: 76a1049b84dd ("clk: ti: am43xx: add new clkctrl data for am43xx")
Signed-off-by: Tony Lindgren &lt;tony@atomide.com&gt;
Link: https://lkml.kernel.org/r/20200221171030.39326-1-tony@atomide.com
Acked-by: Tero Kristo &lt;t-kristo@ti.com&gt;
Signed-off-by: Stephen Boyd &lt;sboyd@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>clk: imx: Align imx sc clock parent msg structs to 4</title>
<updated>2020-04-02T13:11:02+00:00</updated>
<author>
<name>Leonard Crestez</name>
<email>leonard.crestez@nxp.com</email>
</author>
<published>2020-02-20T16:29:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b2efabe3f88cf568537f98c315474ad61e74a3cc'/>
<id>b2efabe3f88cf568537f98c315474ad61e74a3cc</id>
<content type='text'>
commit 8400ab8896324641243b57fc49b448023c07409a upstream.

The imx SC api strongly assumes that messages are composed out of
4-bytes words but some of our message structs have odd sizeofs.

This produces many oopses with CONFIG_KASAN=y.

Fix by marking with __aligned(4).

Fixes: 666aed2d13ee ("clk: imx: scu: add set parent support")
Signed-off-by: Leonard Crestez &lt;leonard.crestez@nxp.com&gt;
Link: https://lkml.kernel.org/r/aad021e432b3062c142973d09b766656eec18fde.1582216144.git.leonard.crestez@nxp.com
Signed-off-by: Stephen Boyd &lt;sboyd@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 8400ab8896324641243b57fc49b448023c07409a upstream.

The imx SC api strongly assumes that messages are composed out of
4-bytes words but some of our message structs have odd sizeofs.

This produces many oopses with CONFIG_KASAN=y.

Fix by marking with __aligned(4).

Fixes: 666aed2d13ee ("clk: imx: scu: add set parent support")
Signed-off-by: Leonard Crestez &lt;leonard.crestez@nxp.com&gt;
Link: https://lkml.kernel.org/r/aad021e432b3062c142973d09b766656eec18fde.1582216144.git.leonard.crestez@nxp.com
Signed-off-by: Stephen Boyd &lt;sboyd@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>clk: imx: Align imx sc clock msg structs to 4</title>
<updated>2020-04-02T13:11:01+00:00</updated>
<author>
<name>Leonard Crestez</name>
<email>leonard.crestez@nxp.com</email>
</author>
<published>2020-02-20T16:29:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4a3c7e1c807f77bd865f584635aeeed36415e04f'/>
<id>4a3c7e1c807f77bd865f584635aeeed36415e04f</id>
<content type='text'>
commit a0ae04a25650fd51b7106e742d27333e502173c6 upstream.

The imx SC api strongly assumes that messages are composed out of
4-bytes words but some of our message structs have odd sizeofs.

This produces many oopses with CONFIG_KASAN=y.

Fix by marking with __aligned(4).

Fixes: fe37b4820417 ("clk: imx: add scu clock common part")
Signed-off-by: Leonard Crestez &lt;leonard.crestez@nxp.com&gt;
Link: https://lkml.kernel.org/r/10e97a04980d933b2cfecb6b124bf9046b6e4f16.1582216144.git.leonard.crestez@nxp.com
Signed-off-by: Stephen Boyd &lt;sboyd@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a0ae04a25650fd51b7106e742d27333e502173c6 upstream.

The imx SC api strongly assumes that messages are composed out of
4-bytes words but some of our message structs have odd sizeofs.

This produces many oopses with CONFIG_KASAN=y.

Fix by marking with __aligned(4).

Fixes: fe37b4820417 ("clk: imx: add scu clock common part")
Signed-off-by: Leonard Crestez &lt;leonard.crestez@nxp.com&gt;
Link: https://lkml.kernel.org/r/10e97a04980d933b2cfecb6b124bf9046b6e4f16.1582216144.git.leonard.crestez@nxp.com
Signed-off-by: Stephen Boyd &lt;sboyd@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>net: ks8851-ml: Fix IO operations, again</title>
<updated>2020-04-02T13:11:01+00:00</updated>
<author>
<name>Marek Vasut</name>
<email>marex@denx.de</email>
</author>
<published>2020-03-25T14:25:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=08479b1391cb6a30b64d63d3aad2f7c85af6b605'/>
<id>08479b1391cb6a30b64d63d3aad2f7c85af6b605</id>
<content type='text'>
commit 8262e6f9b1034ede34548a04dec4c302d92c9497 upstream.

This patch reverts 58292104832f ("net: ks8851-ml: Fix 16-bit IO operation")
and edacb098ea9c ("net: ks8851-ml: Fix 16-bit data access"), because it
turns out these were only necessary due to buggy hardware. This patch adds
a check for such a buggy hardware to prevent any such mistakes again.

While working further on the KS8851 driver, it came to light that the
KS8851-16MLL is capable of switching bus endianness by a hardware strap,
EESK pin. If this strap is incorrect, the IO accesses require such endian
swapping as is being reverted by this patch. Such swapping also impacts
the performance significantly.

Hence, in addition to removing it, detect that the hardware is broken,
report to user, and fail to bind with such hardware.

Fixes: 58292104832f ("net: ks8851-ml: Fix 16-bit IO operation")
Fixes: edacb098ea9c ("net: ks8851-ml: Fix 16-bit data access")
Signed-off-by: Marek Vasut &lt;marex@denx.de&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Lukas Wunner &lt;lukas@wunner.de&gt;
Cc: Petr Stetiar &lt;ynezz@true.cz&gt;
Cc: YueHaibing &lt;yuehaibing@huawei.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 8262e6f9b1034ede34548a04dec4c302d92c9497 upstream.

This patch reverts 58292104832f ("net: ks8851-ml: Fix 16-bit IO operation")
and edacb098ea9c ("net: ks8851-ml: Fix 16-bit data access"), because it
turns out these were only necessary due to buggy hardware. This patch adds
a check for such a buggy hardware to prevent any such mistakes again.

While working further on the KS8851 driver, it came to light that the
KS8851-16MLL is capable of switching bus endianness by a hardware strap,
EESK pin. If this strap is incorrect, the IO accesses require such endian
swapping as is being reverted by this patch. Such swapping also impacts
the performance significantly.

Hence, in addition to removing it, detect that the hardware is broken,
report to user, and fail to bind with such hardware.

Fixes: 58292104832f ("net: ks8851-ml: Fix 16-bit IO operation")
Fixes: edacb098ea9c ("net: ks8851-ml: Fix 16-bit data access")
Signed-off-by: Marek Vasut &lt;marex@denx.de&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Lukas Wunner &lt;lukas@wunner.de&gt;
Cc: Petr Stetiar &lt;ynezz@true.cz&gt;
Cc: YueHaibing &lt;yuehaibing@huawei.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>gpiolib: acpi: Add quirk to ignore EC wakeups on HP x2 10 CHT + AXP288 model</title>
<updated>2020-04-02T13:11:01+00:00</updated>
<author>
<name>Hans de Goede</name>
<email>hdegoede@redhat.com</email>
</author>
<published>2020-03-02T11:12:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=62465fd66323465ca6d928185f2fef3c0ba52705'/>
<id>62465fd66323465ca6d928185f2fef3c0ba52705</id>
<content type='text'>
commit 0c625ccfe6f754d0896b8881f5c85bcb81699f1f upstream.

There are at least 3 models of the HP x2 10 models:

Bay Trail SoC + AXP288 PMIC
Cherry Trail SoC + AXP288 PMIC
Cherry Trail SoC + TI PMIC

Like on the other HP x2 10 models we need to ignore wakeup for ACPI GPIO
events on the external embedded-controller pin to avoid spurious wakeups
on the HP x2 10 CHT + AXP288 model too.

This commit adds an extra DMI based quirk for the HP x2 10 CHT + AXP288
model, ignoring wakeups for ACPI GPIO events on the EC interrupt pin
on this model. This fixes spurious wakeups from suspend on this model.

Fixes: aa23ca3d98f7 ("gpiolib: acpi: Add honor_wakeup module-option + quirk mechanism")
Reported-and-tested-by: Marc Lehmann &lt;schmorp@schmorp.de&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Link: https://lore.kernel.org/r/20200302111225.6641-4-hdegoede@redhat.com
Acked-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 0c625ccfe6f754d0896b8881f5c85bcb81699f1f upstream.

There are at least 3 models of the HP x2 10 models:

Bay Trail SoC + AXP288 PMIC
Cherry Trail SoC + AXP288 PMIC
Cherry Trail SoC + TI PMIC

Like on the other HP x2 10 models we need to ignore wakeup for ACPI GPIO
events on the external embedded-controller pin to avoid spurious wakeups
on the HP x2 10 CHT + AXP288 model too.

This commit adds an extra DMI based quirk for the HP x2 10 CHT + AXP288
model, ignoring wakeups for ACPI GPIO events on the EC interrupt pin
on this model. This fixes spurious wakeups from suspend on this model.

Fixes: aa23ca3d98f7 ("gpiolib: acpi: Add honor_wakeup module-option + quirk mechanism")
Reported-and-tested-by: Marc Lehmann &lt;schmorp@schmorp.de&gt;
Signed-off-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Link: https://lore.kernel.org/r/20200302111225.6641-4-hdegoede@redhat.com
Acked-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>platform/x86: pmc_atom: Add Lex 2I385SW to critclk_systems DMI table</title>
<updated>2020-04-02T13:11:01+00:00</updated>
<author>
<name>Georg Müller</name>
<email>georgmueller@gmx.net</email>
</author>
<published>2020-02-03T20:11:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d3e215554a6c4bd9007db38ba9ea2216b0e8f78d'/>
<id>d3e215554a6c4bd9007db38ba9ea2216b0e8f78d</id>
<content type='text'>
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

Fixes: 648e921888ad ("clk: x86: Stop marking clocks as CLK_IS_CRITICAL")
Tested-by: Georg Müller &lt;georgmueller@gmx.net&gt;
Signed-off-by: Georg Müller &lt;georgmueller@gmx.net&gt;
Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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

Fixes: 648e921888ad ("clk: x86: Stop marking clocks as CLK_IS_CRITICAL")
Tested-by: Georg Müller &lt;georgmueller@gmx.net&gt;
Signed-off-by: Georg Müller &lt;georgmueller@gmx.net&gt;
Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>vt: vt_ioctl: fix use-after-free in vt_in_use()</title>
<updated>2020-04-02T13:11:00+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2020-03-22T03:43:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3f4ba176c6237e291417d0c8f9c1386556dc080d'/>
<id>3f4ba176c6237e291417d0c8f9c1386556dc080d</id>
<content type='text'>
commit 7cf64b18b0b96e751178b8d0505d8466ff5a448f upstream.

vt_in_use() dereferences console_driver-&gt;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-&gt;ttys[i]) != NULL'
and skipping the check of tty_struct::count.  But, looking at
console_driver-&gt;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 &gt; 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 &lt;fcntl.h&gt;
	#include &lt;linux/vt.h&gt;

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

		fd = open("/dev/tty10", O_RDONLY);
		for (nproc = 1; nproc &lt; 8; nproc *= 2)
			fork();
		for (;;) {
			sprintf(ttyname, "/dev/tty%d", rand() % 8);
			close(open(ttyname, O_RDONLY));
			ioctl(fd, VT_GETSTATE, &amp;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
	 [...]

Fixes: 4001d7b7fc27 ("vt: push down the tty lock so we can see what is left to tackle")
Cc: &lt;stable@vger.kernel.org&gt; # v3.4+
Acked-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Link: https://lore.kernel.org/r/20200322034305.210082-3-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 7cf64b18b0b96e751178b8d0505d8466ff5a448f upstream.

vt_in_use() dereferences console_driver-&gt;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-&gt;ttys[i]) != NULL'
and skipping the check of tty_struct::count.  But, looking at
console_driver-&gt;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 &gt; 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 &lt;fcntl.h&gt;
	#include &lt;linux/vt.h&gt;

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

		fd = open("/dev/tty10", O_RDONLY);
		for (nproc = 1; nproc &lt; 8; nproc *= 2)
			fork();
		for (;;) {
			sprintf(ttyname, "/dev/tty%d", rand() % 8);
			close(open(ttyname, O_RDONLY));
			ioctl(fd, VT_GETSTATE, &amp;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
	 [...]

Fixes: 4001d7b7fc27 ("vt: push down the tty lock so we can see what is left to tackle")
Cc: &lt;stable@vger.kernel.org&gt; # v3.4+
Acked-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Link: https://lore.kernel.org/r/20200322034305.210082-3-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>vt: vt_ioctl: fix VT_DISALLOCATE freeing in-use virtual console</title>
<updated>2020-04-02T13:11:00+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2020-03-22T03:43:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=acf0e94019310a9e1c4b6807c208f49a25f74573'/>
<id>acf0e94019310a9e1c4b6807c208f49a25f74573</id>
<content type='text'>
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 &lt;fcntl.h&gt;
	#include &lt;linux/vt.h&gt;
	#include &lt;sys/ioctl.h&gt;
	#include &lt;unistd.h&gt;

	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
	 [...]

Fixes: 4001d7b7fc27 ("vt: push down the tty lock so we can see what is left to tackle")
Cc: &lt;stable@vger.kernel.org&gt; # v3.4+
Reported-by: syzbot+522643ab5729b0421998@syzkaller.appspotmail.com
Acked-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Link: https://lore.kernel.org/r/20200322034305.210082-2-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;fcntl.h&gt;
	#include &lt;linux/vt.h&gt;
	#include &lt;sys/ioctl.h&gt;
	#include &lt;unistd.h&gt;

	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
	 [...]

Fixes: 4001d7b7fc27 ("vt: push down the tty lock so we can see what is left to tackle")
Cc: &lt;stable@vger.kernel.org&gt; # v3.4+
Reported-by: syzbot+522643ab5729b0421998@syzkaller.appspotmail.com
Acked-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Link: https://lore.kernel.org/r/20200322034305.210082-2-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>vt: vt_ioctl: remove unnecessary console allocation checks</title>
<updated>2020-04-02T13:11:00+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2020-02-24T08:03:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d1b6ab26c850ff1e02e895b10e74564a4df12483'/>
<id>d1b6ab26c850ff1e02e895b10e74564a4df12483</id>
<content type='text'>
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.

Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Link: https://lore.kernel.org/r/20200224080326.295046-1-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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.

Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Link: https://lore.kernel.org/r/20200224080326.295046-1-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>vt: switch vt_dont_switch to bool</title>
<updated>2020-04-02T13:11:00+00:00</updated>
<author>
<name>Jiri Slaby</name>
<email>jslaby@suse.cz</email>
</author>
<published>2020-02-19T07:39:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c897e625f94b3dad181362c98f6eef61ef8471a9'/>
<id>c897e625f94b3dad181362c98f6eef61ef8471a9</id>
<content type='text'>
commit f400991bf872debffb01c46da882dc97d7e3248e upstream.

vt_dont_switch is pure boolean, no need for whole char.

Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
Link: https://lore.kernel.org/r/20200219073951.16151-6-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit f400991bf872debffb01c46da882dc97d7e3248e upstream.

vt_dont_switch is pure boolean, no need for whole char.

Signed-off-by: Jiri Slaby &lt;jslaby@suse.cz&gt;
Link: https://lore.kernel.org/r/20200219073951.16151-6-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
</feed>
