KCSAN: data-race in snd_rawmidi_transmit / snd_rawmidi_write

Status: fixed on 2021/03/10 01:49
Subsystems: sound
[Documentation on labels]
Reported-by: syzbot+a23a6f1215c84756577c@syzkaller.appspotmail.com
Fix commit: 88a06d6fd6b3 ALSA: rawmidi: Access runtime->avail always in spinlock
First crash: 2221d, last: 1996d
▶ ▼ Discussions (6)
Title Replies (including bot) Last reply
[PATCH 5.4 00/47] 5.4.87-rc1 review 58 (58) 2021/02/26 14:21
[PATCH 5.10 00/63] 5.10.5-rc1 review 75 (75) 2021/01/07 08:13
[PATCH 4.19 00/35] 4.19.165-rc1 review 44 (44) 2021/01/06 13:46
[PATCH 4.19 00/29] 4.19.165-rc2 review 36 (36) 2021/01/06 13:46
[PATCH AUTOSEL 5.4 001/130] soc: aspeed-lpc-ctrl: Fail probe of lpc-ctrl if reserved memory is not aligned 140 (140) 2021/01/06 07:33
[PATCH AUTOSEL 4.19 01/87] locks: Fix UBSAN undefined behaviour in flock64_to_posix_lock 87 (87) 2020/12/23 02:21
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in snd_rawmidi_transmit / snd_rawmidi_write (2) sound 6 4 1953d 1962d 0/29 auto-closed as invalid on 2021/04/23 19:29

Sample crash report:
==================================================================
BUG: KCSAN: data-race in snd_rawmidi_transmit / snd_rawmidi_write

write to 0xffff8880289c07b8 of 8 bytes by task 2048 on cpu 1:
 __snd_rawmidi_transmit_ack sound/core/rawmidi.c:1267 [inline]
 snd_rawmidi_transmit+0x2b8/0x3b0 sound/core/rawmidi.c:1326
 snd_vmidi_output_work+0xf1/0x200 sound/core/seq/seq_virmidi.c:144
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275
 worker_thread+0x616/0xa70 kernel/workqueue.c:2421
 kthread+0x20b/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read to 0xffff8880289c07b8 of 8 bytes by task 27017 on cpu 0:
 snd_rawmidi_write+0x5ef/0x720 sound/core/rawmidi.c:1489
 vfs_write+0x21a/0x7e0 fs/read_write.c:603
 ksys_write+0xce/0x180 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:667
 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: 27017 Comm: syz-executor.4 Not tainted 5.11.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (232):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/02/04 19:55 upstream 61556703b610 42b90a7c .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in snd_rawmidi_transmit / snd_rawmidi_write
2021/01/07 22:36 upstream f5e6c330254a c104d4a3 .config console log report info ci2-upstream-kcsan-gce
2020/12/16 02:57 upstream d635a69dd498 f213e07e .config console log report info ci2-upstream-kcsan-gce
2020/12/15 20:27 upstream 148842c98a24 f213e07e .config console log report info ci2-upstream-kcsan-gce
2020/12/15 13:32 upstream 148842c98a24 97183ed7 .config console log report info ci2-upstream-kcsan-gce
2020/12/14 21:41 upstream fab0fca1da5c 97183ed7 .config console log report info ci2-upstream-kcsan-gce
2020/12/14 09:39 upstream 2c85ebc57b3e b22a7ec3 .config console log report info ci2-upstream-kcsan-gce
2020/12/13 09:53 upstream 6bff9bb8a292 bca53db9 .config console log report info ci2-upstream-kcsan-gce
2020/12/11 05:29 upstream 9fca90cf2892 f900b48c .config console log report info ci2-upstream-kcsan-gce
2020/12/06 11:24 upstream 7059c2c00a21 f12ba0c5 .config console log report info ci2-upstream-kcsan-gce
2020/12/03 12:53 upstream 34816d20f173 59ad4022 .config console log report info ci2-upstream-kcsan-gce
2020/11/28 04:03 upstream c84e1efae022 486f93ef .config console log report info ci2-upstream-kcsan-gce
2020/11/25 23:49 upstream fa02fcd94b0c 3f581b43 .config console log report info ci2-upstream-kcsan-gce
2020/11/19 16:43 upstream c2e7554e1b85 0767f13f .config console log report info ci2-upstream-kcsan-gce
2020/11/18 18:37 upstream 0fa8ee0d9ab9 0767f13f .config console log report info ci2-upstream-kcsan-gce
2020/11/18 14:00 upstream 0fa8ee0d9ab9 09323409 .config console log report info ci2-upstream-kcsan-gce
2020/11/18 01:45 upstream 111e91a6df50 09323409 .config console log report info ci2-upstream-kcsan-gce
2020/11/17 15:44 upstream 9c87c9f41245 bd2a760b .config console log report info ci2-upstream-kcsan-gce
2020/11/16 19:11 upstream 09162bc32c88 1bf9a662 .config console log report info ci2-upstream-kcsan-gce
2020/11/15 07:24 upstream e28c0d7c92c8 1bf9a662 .config console log report info ci2-upstream-kcsan-gce
2020/11/14 18:04 upstream f01c30de86f1 1bf9a662 .config console log report info ci2-upstream-kcsan-gce
2020/11/14 10:04 upstream 9e6a39eae450 1bf9a662 .config console log report info ci2-upstream-kcsan-gce
2020/11/08 05:08 upstream 4429f14aeea9 cba33199 .config console log report info ci2-upstream-kcsan-gce
2020/11/06 01:33 upstream 521b619acdc8 cba33199 .config console log report info ci2-upstream-kcsan-gce
2020/11/05 15:32 upstream 4ef8451b3326 cba33199 .config console log report info ci2-upstream-kcsan-gce
2020/11/01 22:03 upstream 31f020064f9d 8bc4594f .config console log report info ci2-upstream-kcsan-gce
2020/11/01 08:03 upstream c2dc4c073fb7 8bc4594f .config console log report info ci2-upstream-kcsan-gce
2020/10/31 00:42 upstream f5d808567a51 18e33098 .config console log report info ci2-upstream-kcsan-gce
2020/10/29 22:02 upstream 23859ae44402 a0c7169a .config console log report info ci2-upstream-kcsan-gce
2020/10/27 20:14 upstream 4525c8781ec0 94942294 .config console log report info ci2-upstream-kcsan-gce
2020/10/27 09:29 upstream 41ba50b0572e 8b3eaf58 .config console log report info ci2-upstream-kcsan-gce
2020/10/20 16:53 upstream 270315b8235e ff4a3345 .config console log report info ci2-upstream-kcsan-gce
2020/10/20 02:43 upstream bbe85027ce80 ff4a3345 .config console log report info ci2-upstream-kcsan-gce
2020/10/19 17:00 upstream 7cf726a59435 ff4a3345 .config console log report info ci2-upstream-kcsan-gce
2020/10/19 00:35 upstream 9453b2d4694c fea47c01 .config console log report info ci2-upstream-kcsan-gce
2020/10/18 04:20 upstream 9d9af1007bc0 fea47c01 .config console log report info ci2-upstream-kcsan-gce
2020/10/16 23:42 upstream 54a4c789ca80 6e262c73 .config console log report info ci2-upstream-kcsan-gce
2020/10/16 11:31 upstream 9ff9b0d392ea 6e262c73 .config console log report info ci2-upstream-kcsan-gce
2020/10/16 04:05 upstream 726eb70e0d34 6e262c73 .config console log report info ci2-upstream-kcsan-gce
2020/10/15 05:08 upstream 3e4fb4346c78 fc7735a2 .config console log report info ci2-upstream-kcsan-gce
2020/10/11 21:41 upstream 3dd0130f2430 4a77ae0b .config console log report info ci2-upstream-kcsan-gce
2020/10/11 02:30 upstream da690031a5d6 4a77ae0b .config console log report info ci2-upstream-kcsan-gce
2020/08/12 16:13 upstream fb893de323e2 0d7bd2e0 .config console log report ci2-upstream-kcsan-gce
2020/06/24 19:57 upstream 26e122e97a3d 9d60b18e .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.