syzbot


KCSAN: data-race in snd_pcm_oss_change_params_locked / snd_pcm_oss_poll

Status: auto-closed as invalid on 2020/12/21 11:53
Subsystems: sound
[Documentation on labels]
Reported-by: syzbot+3832818348b59ecc2834@syzkaller.appspotmail.com
First crash: 1243d, last: 1230d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in snd_pcm_oss_change_params_locked / snd_pcm_oss_poll

read to 0xffff88801168f700 of 1 bytes by task 18094 on cpu 1:
 snd_pcm_oss_change_params_locked+0x1c9f/0x2600 sound/core/oss/pcm_oss.c:981
 snd_pcm_oss_make_ready_locked sound/core/oss/pcm_oss.c:1166 [inline]
 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1494 [inline]
 snd_pcm_oss_read+0x1a8/0x8a0 sound/core/oss/pcm_oss.c:2742
 do_loop_readv_writev fs/read_write.c:761 [inline]
 do_iter_read+0x2be/0x4b0 fs/read_write.c:803
 vfs_readv fs/read_write.c:921 [inline]
 do_readv+0x13d/0x280 fs/read_write.c:958
 __do_sys_readv fs/read_write.c:1049 [inline]
 __se_sys_readv fs/read_write.c:1046 [inline]
 __x64_sys_readv+0x41/0x50 fs/read_write.c:1046
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff88801168f700 of 1 bytes by task 18083 on cpu 0:
 snd_pcm_oss_poll+0x417/0x510 sound/core/oss/pcm_oss.c:2830
 vfs_poll include/linux/poll.h:90 [inline]
 do_pollfd fs/select.c:869 [inline]
 do_poll fs/select.c:917 [inline]
 do_sys_poll+0x611/0xb80 fs/select.c:1011
 __do_sys_ppoll fs/select.c:1111 [inline]
 __se_sys_ppoll+0x169/0x1b0 fs/select.c:1091
 __x64_sys_ppoll+0x63/0x70 fs/select.c:1091
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 18083 Comm: syz-executor.0 Not tainted 5.10.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/11/14 14:55 upstream f01c30de86f1 1bf9a662 .config console log report info ci2-upstream-kcsan-gce
2020/11/02 04:33 upstream 31f020064f9d 8bc4594f .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.