Takashi Iwai 00a7a75559 ALSA: dummy: Fix a use-after-free at closing ... commit d5dbbe6569481bf12dcbe3e12cff72c5f78d272c upstream. syzkaller fuzzer spotted a potential use-after-free case in snd-dummy driver when hrtimer is used as backend: > ================================================================== > BUG: KASAN: use-after-free in rb_erase+0x1b17/0x2010 at addr ffff88005e5b6f68 > Read of size 8 by task syz-executor/8984 > ============================================================================= > BUG kmalloc-192 (Not tainted): kasan: bad access detected > ----------------------------------------------------------------------------- > > Disabling lock debugging due to kernel taint > INFO: Allocated in 0xbbbbbbbbbbbbbbbb age=18446705582212484632 > .... > [< none >] dummy_hrtimer_create+0x49/0x1a0 sound/drivers/dummy.c:464 > .... > INFO: Freed in 0xfffd8e09 age=18446705496313138713 cpu=2164287125 pid=-1 > [< none >] dummy_hrtimer_free+0x68/0x80 sound/drivers/dummy.c:481 > .... > Call Trace: > [<ffffffff8179e59e>] __asan_report_load8_noabort+0x3e/0x40 mm/kasan/report.c:333 > [< inline >] rb_set_parent include/linux/rbtree_augmented.h:111 > [< inline >] __rb_erase_augmented include/linux/rbtree_augmented.h:218 > [<ffffffff82ca5787>] rb_erase+0x1b17/0x2010 lib/rbtree.c:427 > [<ffffffff82cb02e8>] timerqueue_del+0x78/0x170 lib/timerqueue.c:86 > [<ffffffff814d0c80>] __remove_hrtimer+0x90/0x220 kernel/time/hrtimer.c:903 > [< inline >] remove_hrtimer kernel/time/hrtimer.c:945 > [<ffffffff814d23da>] hrtimer_try_to_cancel+0x22a/0x570 kernel/time/hrtimer.c:1046 > [<ffffffff814d2742>] hrtimer_cancel+0x22/0x40 kernel/time/hrtimer.c:1066 > [<ffffffff85420531>] dummy_hrtimer_stop+0x91/0xb0 sound/drivers/dummy.c:417 > [<ffffffff854228bf>] dummy_pcm_trigger+0x17f/0x1e0 sound/drivers/dummy.c:507 > [<ffffffff85392170>] snd_pcm_do_stop+0x160/0x1b0 sound/core/pcm_native.c:1106 > [<ffffffff85391b26>] snd_pcm_action_single+0x76/0x120 sound/core/pcm_native.c:956 > [<ffffffff85391e01>] snd_pcm_action+0x231/0x290 sound/core/pcm_native.c:974 > [< inline >] snd_pcm_stop sound/core/pcm_native.c:1139 > [<ffffffff8539754d>] snd_pcm_drop+0x12d/0x1d0 sound/core/pcm_native.c:1784 > [<ffffffff8539d3be>] snd_pcm_common_ioctl1+0xfae/0x2150 sound/core/pcm_native.c:2805 > [<ffffffff8539ee91>] snd_pcm_capture_ioctl1+0x2a1/0x5e0 sound/core/pcm_native.c:2976 > [<ffffffff8539f2ec>] snd_pcm_kernel_ioctl+0x11c/0x160 sound/core/pcm_native.c:3020 > [<ffffffff853d9a44>] snd_pcm_oss_sync+0x3a4/0xa30 sound/core/oss/pcm_oss.c:1693 > [<ffffffff853da27d>] snd_pcm_oss_release+0x1ad/0x280 sound/core/oss/pcm_oss.c:2483 > ..... A workaround is to call hrtimer_cancel() in dummy_hrtimer_sync() which is called certainly before other blocking ops. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Willy Tarreau <w@1wt.eu>		2019-07-27 21:41:56 +02:00
..
mpu401
opl3
opl4
pcsp
vx
aloop.c
dummy.c	ALSA: dummy: Fix a use-after-free at closing	2019-07-27 21:41:56 +02:00
Kconfig
Makefile
ml403-ac97cr.c
mtpav.c
mts64.c
pcm-indirect2.c
pcm-indirect2.h
portman2x4.c
serial-u16550.c
virmidi.c