linux-stable.git, branch v5.5.2 Linux kernel stable tree Linux 5.5.2 2020-02-04T18:18:03+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2020-02-04T18:18:03+00:00 567f0ad8b0b773cc886906514b6c1ccbd1335a41 






btrfs: do not zero f_bavail if we have available space
2020-02-04T18:18:03+00:00

Josef Bacik
josef@toxicpanda.com

2020-01-31T14:31:05+00:00

165387a9c90152f35976d82feca6eff5f0d5ac02

commit d55966c4279bfc6a0cf0b32bf13f5df228a1eeb6 upstream.

There was some logic added a while ago to clear out f_bavail in statfs()
if we did not have enough free metadata space to satisfy our global
reserve.  This was incorrect at the time, however didn't really pose a
problem for normal file systems because we would often allocate chunks
if we got this low on free metadata space, and thus wouldn't really hit
this case unless we were actually full.

Fast forward to today and now we are much better about not allocating
metadata chunks all of the time.  Couple this with d792b0f19711 ("btrfs:
always reserve our entire size for the global reserve") which now means
we'll easily have a larger global reserve than our free space, we are
now more likely to trip over this while still having plenty of space.

Fix this by skipping this logic if the global rsv's space_info is not
full.  space_info->full is 0 unless we've attempted to allocate a chunk
for that space_info and that has failed.  If this happens then the space
for the global reserve is definitely sacred and we need to report
b_avail == 0, but before then we can just use our calculated b_avail.

Reported-by: Martin Steigerwald <martin@lichtvoll.de>
Fixes: ca8a51b3a979 ("btrfs: statfs: report zero available if metadata are exhausted")
CC: stable@vger.kernel.org # 4.5+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Tested-By: Martin Steigerwald <martin@lichtvoll.de>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit d55966c4279bfc6a0cf0b32bf13f5df228a1eeb6 upstream.

There was some logic added a while ago to clear out f_bavail in statfs()
if we did not have enough free metadata space to satisfy our global
reserve.  This was incorrect at the time, however didn't really pose a
problem for normal file systems because we would often allocate chunks
if we got this low on free metadata space, and thus wouldn't really hit
this case unless we were actually full.

Fast forward to today and now we are much better about not allocating
metadata chunks all of the time.  Couple this with d792b0f19711 ("btrfs:
always reserve our entire size for the global reserve") which now means
we'll easily have a larger global reserve than our free space, we are
now more likely to trip over this while still having plenty of space.

Fix this by skipping this logic if the global rsv's space_info is not
full.  space_info->full is 0 unless we've attempted to allocate a chunk
for that space_info and that has failed.  If this happens then the space
for the global reserve is definitely sacred and we need to report
b_avail == 0, but before then we can just use our calculated b_avail.

Reported-by: Martin Steigerwald <martin@lichtvoll.de>
Fixes: ca8a51b3a979 ("btrfs: statfs: report zero available if metadata are exhausted")
CC: stable@vger.kernel.org # 4.5+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Tested-By: Martin Steigerwald <martin@lichtvoll.de>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








cgroup: Prevent double killing of css when enabling threaded cgroup
2020-02-04T18:18:03+00:00

Michal Koutný
mkoutny@suse.com

2020-01-09T15:05:59+00:00

5c41180d719de814d686536e335651299da5a4b3

commit 3bc0bb36fa30e95ca829e9cf480e1ef7f7638333 upstream.

The test_cgcore_no_internal_process_constraint_on_threads selftest when
running with subsystem controlling noise triggers two warnings:

> [  597.443115] WARNING: CPU: 1 PID: 28167 at kernel/cgroup/cgroup.c:3131 cgroup_apply_control_enable+0xe0/0x3f0
> [  597.443413] WARNING: CPU: 1 PID: 28167 at kernel/cgroup/cgroup.c:3177 cgroup_apply_control_disable+0xa6/0x160

Both stem from a call to cgroup_type_write. The first warning was also
triggered by syzkaller.

When we're switching cgroup to threaded mode shortly after a subsystem
was disabled on it, we can see the respective subsystem css dying there.

The warning in cgroup_apply_control_enable is harmless in this case
since we're not adding new subsys anyway.
The warning in cgroup_apply_control_disable indicates an attempt to kill
css of recently disabled subsystem repeatedly.

The commit prevents these situations by making cgroup_type_write wait
for all dying csses to go away before re-applying subtree controls.
When at it, the locations of WARN_ON_ONCE calls are moved so that
warning is triggered only when we are about to misuse the dying css.

Reported-by: syzbot+5493b2a54d31d6aea629@syzkaller.appspotmail.com
Reported-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit 3bc0bb36fa30e95ca829e9cf480e1ef7f7638333 upstream.

The test_cgcore_no_internal_process_constraint_on_threads selftest when
running with subsystem controlling noise triggers two warnings:

> [  597.443115] WARNING: CPU: 1 PID: 28167 at kernel/cgroup/cgroup.c:3131 cgroup_apply_control_enable+0xe0/0x3f0
> [  597.443413] WARNING: CPU: 1 PID: 28167 at kernel/cgroup/cgroup.c:3177 cgroup_apply_control_disable+0xa6/0x160

Both stem from a call to cgroup_type_write. The first warning was also
triggered by syzkaller.

When we're switching cgroup to threaded mode shortly after a subsystem
was disabled on it, we can see the respective subsystem css dying there.

The warning in cgroup_apply_control_enable is harmless in this case
since we're not adding new subsys anyway.
The warning in cgroup_apply_control_disable indicates an attempt to kill
css of recently disabled subsystem repeatedly.

The commit prevents these situations by making cgroup_type_write wait
for all dying csses to go away before re-applying subtree controls.
When at it, the locations of WARN_ON_ONCE calls are moved so that
warning is triggered only when we are about to misuse the dying css.

Reported-by: syzbot+5493b2a54d31d6aea629@syzkaller.appspotmail.com
Reported-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








Bluetooth: Fix race condition in hci_release_sock()
2020-02-04T18:18:03+00:00

Dan Carpenter
dan.carpenter@oracle.com

2020-01-15T17:49:04+00:00

6d0a10479ec1713a4e8df897273209a0f791ca49

commit 11eb85ec42dc8c7a7ec519b90ccf2eeae9409de8 upstream.

Syzbot managed to trigger a use after free "KASAN: use-after-free Write
in hci_sock_bind".  I have reviewed the code manually and one possibly
cause I have found is that we are not holding lock_sock(sk) when we do
the hci_dev_put(hdev) in hci_sock_release().  My theory is that the bind
and the release are racing against each other which results in this use
after free.

Reported-by: syzbot+eba992608adf3d796bcc@syzkaller.appspotmail.com
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit 11eb85ec42dc8c7a7ec519b90ccf2eeae9409de8 upstream.

Syzbot managed to trigger a use after free "KASAN: use-after-free Write
in hci_sock_bind".  I have reviewed the code manually and one possibly
cause I have found is that we are not holding lock_sock(sk) when we do
the hci_dev_put(hdev) in hci_sock_release().  My theory is that the bind
and the release are racing against each other which results in this use
after free.

Reported-by: syzbot+eba992608adf3d796bcc@syzkaller.appspotmail.com
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








ttyprintk: fix a potential deadlock in interrupt context issue
2020-02-04T18:18:03+00:00

Zhenzhong Duan
zhenzhong.duan@gmail.com

2020-01-13T03:48:42+00:00

6374fd5b64df1e447fb00888bb0a629f4ed6d20a

commit 9a655c77ff8fc65699a3f98e237db563b37c439b upstream.

tpk_write()/tpk_close() could be interrupted when holding a mutex, then
in timer handler tpk_write() may be called again trying to acquire same
mutex, lead to deadlock.

Google syzbot reported this issue with CONFIG_DEBUG_ATOMIC_SLEEP
enabled:

BUG: sleeping function called from invalid context at
kernel/locking/mutex.c:938
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/1
1 lock held by swapper/1/0:
...
Call Trace:
  <IRQ>
  dump_stack+0x197/0x210
  ___might_sleep.cold+0x1fb/0x23e
  __might_sleep+0x95/0x190
  __mutex_lock+0xc5/0x13c0
  mutex_lock_nested+0x16/0x20
  tpk_write+0x5d/0x340
  resync_tnc+0x1b6/0x320
  call_timer_fn+0x1ac/0x780
  run_timer_softirq+0x6c3/0x1790
  __do_softirq+0x262/0x98c
  irq_exit+0x19b/0x1e0
  smp_apic_timer_interrupt+0x1a3/0x610
  apic_timer_interrupt+0xf/0x20
  </IRQ>

See link https://syzkaller.appspot.com/bug?extid=2eeef62ee31f9460ad65 for
more details.

Fix it by using spinlock in process context instead of mutex and having
interrupt disabled in critical section.

Reported-by: syzbot+2eeef62ee31f9460ad65@syzkaller.appspotmail.com
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20200113034842.435-1-zhenzhong.duan@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit 9a655c77ff8fc65699a3f98e237db563b37c439b upstream.

tpk_write()/tpk_close() could be interrupted when holding a mutex, then
in timer handler tpk_write() may be called again trying to acquire same
mutex, lead to deadlock.

Google syzbot reported this issue with CONFIG_DEBUG_ATOMIC_SLEEP
enabled:

BUG: sleeping function called from invalid context at
kernel/locking/mutex.c:938
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/1
1 lock held by swapper/1/0:
...
Call Trace:
  <IRQ>
  dump_stack+0x197/0x210
  ___might_sleep.cold+0x1fb/0x23e
  __might_sleep+0x95/0x190
  __mutex_lock+0xc5/0x13c0
  mutex_lock_nested+0x16/0x20
  tpk_write+0x5d/0x340
  resync_tnc+0x1b6/0x320
  call_timer_fn+0x1ac/0x780
  run_timer_softirq+0x6c3/0x1790
  __do_softirq+0x262/0x98c
  irq_exit+0x19b/0x1e0
  smp_apic_timer_interrupt+0x1a3/0x610
  apic_timer_interrupt+0xf/0x20
  </IRQ>

See link https://syzkaller.appspot.com/bug?extid=2eeef62ee31f9460ad65 for
more details.

Fix it by using spinlock in process context instead of mutex and having
interrupt disabled in critical section.

Reported-by: syzbot+2eeef62ee31f9460ad65@syzkaller.appspotmail.com
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20200113034842.435-1-zhenzhong.duan@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








tomoyo: Use atomic_t for statistics counter
2020-02-04T18:18:02+00:00

Tetsuo Handa
penguin-kernel@I-love.SAKURA.ne.jp

2020-01-02T03:53:49+00:00

9db441e545d5dd91a97726ea0e9776fe80d8eba4

commit a8772fad0172aeae339144598b809fd8d4823331 upstream.

syzbot is reporting that there is a race at tomoyo_stat_update() [1].
Although it is acceptable to fail to track exact number of times policy
was updated, convert to atomic_t because this is not a hot path.

[1] https://syzkaller.appspot.com/bug?id=a4d7b973972eeed410596e6604580e0133b0fc04

Reported-by: syzbot <syzbot+efea72d4a0a1d03596cd@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit a8772fad0172aeae339144598b809fd8d4823331 upstream.

syzbot is reporting that there is a race at tomoyo_stat_update() [1].
Although it is acceptable to fail to track exact number of times policy
was updated, convert to atomic_t because this is not a hot path.

[1] https://syzkaller.appspot.com/bug?id=a4d7b973972eeed410596e6604580e0133b0fc04

Reported-by: syzbot <syzbot+efea72d4a0a1d03596cd@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








media: dvb-usb/dvb-usb-urb.c: initialize actlen to 0
2020-02-04T18:18:02+00:00

Hans Verkuil
hverkuil-cisco@xs4all.nl

2019-11-12T09:22:28+00:00

a5491f38c7299b4b27d83d88f208ec05e73e0e3d

commit 569bc8d6a6a50acb5fcf07fb10b8d2d461fdbf93 upstream.

This fixes a syzbot failure since actlen could be uninitialized,
but it was still used.

Syzbot link:

https://syzkaller.appspot.com/bug?extid=6bf9606ee955b646c0e1

Reported-and-tested-by: syzbot+6bf9606ee955b646c0e1@syzkaller.appspotmail.com

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit 569bc8d6a6a50acb5fcf07fb10b8d2d461fdbf93 upstream.

This fixes a syzbot failure since actlen could be uninitialized,
but it was still used.

Syzbot link:

https://syzkaller.appspot.com/bug?extid=6bf9606ee955b646c0e1

Reported-and-tested-by: syzbot+6bf9606ee955b646c0e1@syzkaller.appspotmail.com

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








media: gspca: zero usb_buf
2020-02-04T18:18:02+00:00

Hans Verkuil
hverkuil-cisco@xs4all.nl

2019-11-12T09:22:24+00:00

d7c47ec04e3171c13df53bc88cf0bc364820f48d

commit de89d0864f66c2a1b75becfdd6bf3793c07ce870 upstream.

Allocate gspca_dev->usb_buf with kzalloc instead of kmalloc to
ensure it is property zeroed. This fixes various syzbot errors
about uninitialized data.

Syzbot links:

https://syzkaller.appspot.com/bug?extid=32310fc2aea76898d074
https://syzkaller.appspot.com/bug?extid=99706d6390be1ac542a2
https://syzkaller.appspot.com/bug?extid=64437af5c781a7f0e08e

Reported-and-tested-by: syzbot+32310fc2aea76898d074@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+99706d6390be1ac542a2@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+64437af5c781a7f0e08e@syzkaller.appspotmail.com

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit de89d0864f66c2a1b75becfdd6bf3793c07ce870 upstream.

Allocate gspca_dev->usb_buf with kzalloc instead of kmalloc to
ensure it is property zeroed. This fixes various syzbot errors
about uninitialized data.

Syzbot links:

https://syzkaller.appspot.com/bug?extid=32310fc2aea76898d074
https://syzkaller.appspot.com/bug?extid=99706d6390be1ac542a2
https://syzkaller.appspot.com/bug?extid=64437af5c781a7f0e08e

Reported-and-tested-by: syzbot+32310fc2aea76898d074@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+99706d6390be1ac542a2@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+64437af5c781a7f0e08e@syzkaller.appspotmail.com

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








media: vp7045: do not read uninitialized values if usb transfer fails
2020-02-04T18:18:02+00:00

Sean Young
sean@mess.org

2019-11-10T10:25:13+00:00

78765f883b67f186118a788be8de2f7b1a973f3e

commit 26cff637121d8bb866ebd6515c430ac890e6ec80 upstream.

It is not a fatal error if reading the mac address or the remote control
decoder state fails.

Reported-by: syzbot+ec869945d3dde5f33b43@syzkaller.appspotmail.com
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit 26cff637121d8bb866ebd6515c430ac890e6ec80 upstream.

It is not a fatal error if reading the mac address or the remote control
decoder state fails.

Reported-by: syzbot+ec869945d3dde5f33b43@syzkaller.appspotmail.com
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








media: af9005: uninitialized variable printked
2020-02-04T18:18:02+00:00

Sean Young
sean@mess.org

2019-11-10T10:15:37+00:00

003f1a9418de314cecda868bc2a5048b01ce5d8d

commit 51d0c99b391f0cac61ad7b827c26f549ee55672c upstream.

If usb_bulk_msg() fails, actual_length can be uninitialized.

Reported-by: syzbot+9d42b7773d2fecd983ab@syzkaller.appspotmail.com
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit 51d0c99b391f0cac61ad7b827c26f549ee55672c upstream.

If usb_bulk_msg() fails, actual_length can be uninitialized.

Reported-by: syzbot+9d42b7773d2fecd983ab@syzkaller.appspotmail.com
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>