If a request was queued without a control handler object, and
a control handler object is then created and bound to the request
when copying controls on request completion, then a WARN_ON in
mc-request.c is triggered since at that time the request is in
state QUEUED, and not UPDATING.
But this is too strict, and in this case it must also allow
binding objects when in state QUEUED.
This patch was unfortunately lost when the "always copy the controls
on completion" patch was posted, it should have been part of that
commit.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Fixes: c3bf5129f3 ("media: v4l2-ctrls: always copy the controls on completion")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Syzbot reports a NULL-ptr deref in the kref_put() call:
BUG: KASAN: null-ptr-deref in media_request_put drivers/media/mc/mc-request.c:81 [inline]
kref_put include/linux/kref.h:64 [inline]
media_request_put drivers/media/mc/mc-request.c:81 [inline]
media_request_close+0x4d/0x170 drivers/media/mc/mc-request.c:89
__fput+0x2ed/0x750 fs/file_table.c:281
task_work_run+0x147/0x1d0 kernel/task_work.c:123
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_usermode_loop arch/x86/entry/common.c:165 [inline]
prepare_exit_to_usermode+0x48e/0x600 arch/x86/entry/common.c:196
What led to this crash was an injected memory allocation failure in
media_request_alloc():
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
should_failslab+0x5/0x20
kmem_cache_alloc_trace+0x57/0x300
? anon_inode_getfile+0xe5/0x170
media_request_alloc+0x339/0x440
media_device_request_alloc+0x94/0xc0
media_device_ioctl+0x1fb/0x330
? do_vfs_ioctl+0x6ea/0x1a00
? media_ioctl+0x101/0x120
? __media_device_usb_init+0x430/0x430
? media_poll+0x110/0x110
__se_sys_ioctl+0xf9/0x160
do_syscall_64+0xf3/0x1b0
When that allocation fails, filp->private_data is left uninitialized
which media_request_close() does not expect and crashes.
To avoid this, reorder media_request_alloc() such that
allocating the struct file happens as the last step thus
media_request_close() will no longer get called for a partially created
media request.
Reported-by: syzbot+6bed2d543cf7e48b822b@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Fixes: 10905d70d7 ("media: media-request: implement media requests")
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
It is really weird that the media controller sources are all top-level
in drivers/media. It is a bit of a left-over from long ago when most
media sources were all at the top-level. At some point we reorganized
the directory structure, but the media-*.c sources where never moved
to their own directory.
So create a new mc directory and move all sources there. Also rename
the prefix from media- to mc-.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-05-28 12:15:46 -04:00
Renamed from drivers/media/media-request.c (Browse further)
