syzbot


KCSAN: data-race in _prb_read_valid / prb_reserve

Status: moderation: reported on 2020/11/09 13:24
Subsystems: audit
[Documentation on labels]
Reported-by: syzbot+615128043c250cbd858b@syzkaller.appspotmail.com
First crash: 1625d, last: 1d03h

Sample crash report:
EXT4-fs (loop8): mounted filesystem 00000000-0000-0000-0000-000000000000 ro without journal. Quota mode: writeback.
==================================================================
BUG: KCSAN: data-race in _prb_read_valid / prb_reserve

write to 0xffffffff868d7950 of 8 bytes by task 14857 on cpu 1:
 prb_reserve+0x750/0xb80 kernel/printk/printk_ringbuffer.c:-1
 vprintk_store+0x552/0x860 kernel/printk/printk.c:2326
 vprintk_emit+0x174/0x6a0 kernel/printk/printk.c:2408
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2447
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x7f/0xb0 kernel/printk/printk.c:2457
 __ext4_msg+0x198/0x1b0 fs/ext4/super.c:998
 ext4_put_super+0x91/0x820 fs/ext4/super.c:1303
 generic_shutdown_super+0xe5/0x220 fs/super.c:642
 kill_block_super+0x2a/0x70 fs/super.c:1710
 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7368
 deactivate_locked_super+0x7d/0x1c0 fs/super.c:473
 deactivate_super+0x9f/0xb0 fs/super.c:506
 cleanup_mnt+0x26e/0x2e0 fs/namespace.c:1435
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1442
 task_work_run+0x13c/0x1b0 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xa8/0x120 kernel/entry/common.c:218
 do_syscall_64+0xd6/0x1c0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff868d7950 of 8 bytes by task 14847 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:486 [inline]
 prb_first_seq kernel/printk/printk_ringbuffer.c:1957 [inline]
 _prb_read_valid+0x471/0x6c0 kernel/printk/printk_ringbuffer.c:2114
 prb_read_valid+0x42/0x70 kernel/printk/printk_ringbuffer.c:2182
 printk_get_next_message+0xdc/0x530 kernel/printk/printk.c:2987
 console_emit_next_record kernel/printk/printk.c:3074 [inline]
 console_flush_all+0x2a9/0x7a0 kernel/printk/printk.c:3208
 __console_flush_and_unlock kernel/printk/printk.c:3267 [inline]
 console_unlock+0xf4/0x350 kernel/printk/printk.c:3307
 vprintk_emit+0x414/0x6a0 kernel/printk/printk.c:2432
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2447
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x7f/0xb0 kernel/printk/printk.c:2457
 __ext4_msg+0x198/0x1b0 fs/ext4/super.c:998
 ext4_fill_super+0x17b4/0x3650 fs/ext4/super.c:5737
 get_tree_bdev_flags+0x2b4/0x330 fs/super.c:1636
 get_tree_bdev+0x1f/0x30 fs/super.c:1659
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5754
 vfs_get_tree+0x56/0x1e0 fs/super.c:1759
 do_new_mount+0x246/0x6b0 fs/namespace.c:3878
 path_mount+0x49b/0xb30 fs/namespace.c:4205
 do_mount fs/namespace.c:4218 [inline]
 __do_sys_mount fs/namespace.c:4429 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4406
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4406
 x64_sys_call+0xd11/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000ba2 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 14847 Comm: syz.8.4177 Not tainted 6.14.0-syzkaller-03576-g1e1ba8d23dae #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================
EXT4-fs (loop8): warning: mounting fs with errors, running e2fsck is recommended
[EXT4 FS bs=4096, gc=1, bpg=32768, ipg=32, mo=8856c01c, mo2=0002]
EXT4-fs warning (device loop8): ext4_enable_quotas:7145: Failed to enable quota tracking (type=2, err=-22, ino=15). Please run e2fsck to fix.

Crashes (3578):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/27 03:21 upstream 1e1ba8d23dae 20510e88 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/27 00:34 upstream 2df0c02dab82 20510e88 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/26 06:20 upstream 2df0c02dab82 89d30d73 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/25 07:19 upstream 3ba7dfb8da62 875573af .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/25 03:11 upstream 38fec10eb60d 875573af .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/24 06:51 upstream 586de92313fc 875573af .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/23 20:07 upstream 586de92313fc 4e8d3850 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/23 06:53 upstream 183601b78a9b 4e8d3850 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/22 14:12 upstream 88d324e69ea9 c6512ef7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/21 23:06 upstream d07de43e3f05 c6512ef7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/21 15:11 upstream b3ee1e460951 62330552 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/21 01:15 upstream 5fc319360819 62330552 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/20 08:32 upstream a7f2e10ecd8f 9209bc22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/20 00:23 upstream a7f2e10ecd8f e20d7b13 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/19 16:55 upstream 81e4f8d68c66 e20d7b13 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/19 13:03 upstream 81e4f8d68c66 8d0a2921 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/19 01:21 upstream 76b6905c11fd 22a6c2b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/18 08:32 upstream fc444ada1310 ce3352cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/18 02:52 upstream 4701f33a1070 ce3352cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/16 22:45 upstream cb82ca153949 e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/16 07:47 upstream 31d7109a19f6 e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/16 01:23 upstream 3571e8b091f4 e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/15 08:57 upstream a29967be967e e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/14 16:32 upstream 695caca9345a e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/13 10:28 upstream b7f94fcf5546 44be8b44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/13 01:08 upstream 0fed89a961ea 1a5d9317 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/11 21:59 upstream 0b46b049d6ec 16256247 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/11 09:09 upstream 4d872d51bc9d 16256247 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/09 20:50 upstream 1110ce6a1e34 163f510d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/09 04:18 upstream b7c90e3e717a 163f510d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/08 06:53 upstream 21e4543a2e2f 7e3bd60d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/07 15:43 upstream 00a7d39898c8 7e3bd60d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/07 12:39 upstream 0f52fd4f67c6 831e3629 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/06 20:12 upstream 848e07631744 831e3629 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/06 04:25 upstream bb2281fb05e5 831e3629 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/05 12:15 upstream 48a5eed9ad58 60f5d8d9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/04 21:51 upstream 48a5eed9ad58 c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/03 23:28 upstream 99fa936e8e4f c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/03 07:12 upstream b91872c56940 c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/02 16:15 upstream ece144f151ac c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/01 20:39 upstream 03d38806a902 c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/03/01 06:06 upstream 7a5668899f54 67cf5345 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/02/28 17:51 upstream 76544811c850 67cf5345 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/02/27 02:41 upstream 5394eea10651 6a8fcbc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/02/25 22:44 upstream 2a1944bff549 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/02/24 06:42 upstream d082ecbc71e9 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/02/23 16:46 upstream 27102b38b8ca d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/02/22 23:48 upstream 5cf80612d3f7 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2025/02/22 13:52 upstream ff202c5028a1 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _prb_read_valid / prb_reserve
2021/01/17 12:41 upstream 0da0a8a0a0e1 813be542 .config console log report info ci2-upstream-kcsan-gce
2020/11/09 09:54 upstream f8394f232b1e cba33199 .config console log report info ci2-upstream-kcsan-gce
2020/11/07 20:52 upstream 659caaf65dc9 cba33199 .config console log report info ci2-upstream-kcsan-gce
2020/10/14 17:14 upstream b5fc7a89e58b fc7735a2 .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.