syzbot


KCSAN: data-race in find_get_block_common / has_bh_in_lru

Status: moderation: reported on 2025/04/26 16:25
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+a4a07f98f629cf636e9e@syzkaller.appspotmail.com
First crash: 325d, last: 6d13h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
128f25fd-1282-4377-92a5-96cbe8babeef assessment-kcsan Benign: ✅  Confident: ✅  KCSAN: data-race in find_get_block_common / has_bh_in_lru 2026/01/15 18:44 2026/01/15 18:44 2026/01/15 18:49 a9d6a79219801d2130df3b1a792c57f0e5428e9f

Sample crash report:
==================================================================
BUG: KCSAN: data-race in find_get_block_common / has_bh_in_lru

read-write to 0xffff888237c27760 of 8 bytes by task 3764 on cpu 0:
 bh_lru_install fs/buffer.c:1342 [inline]
 find_get_block_common+0x459/0x8a0 fs/buffer.c:1407
 bdev_getblk+0x4d/0x3f0 include/linux/gfp.h:-1
 __bread_gfp+0x51/0x240 fs/buffer.c:1512
 sb_bread include/linux/buffer_head.h:346 [inline]
 isofs_fill_super+0x45e/0x12f0 fs/isofs/inode.c:632
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1694
 get_tree_bdev+0x1f/0x30 fs/super.c:1717
 isofs_get_tree+0x1c/0x30 fs/isofs/inode.c:1538
 vfs_get_tree+0x57/0x1d0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3763 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3839
 path_mount+0x4d0/0xbc0 fs/namespace.c:4159
 do_mount fs/namespace.c:4172 [inline]
 __do_sys_mount fs/namespace.c:4361 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4338
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4338
 x64_sys_call+0x2d61/0x3020 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c27760 of 8 bytes by task 3298 on cpu 1:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1548
 smp_call_function_many_cond+0x2c1/0xc30 kernel/smp.c:821
 on_each_cpu_cond_mask+0x3c/0x80 kernel/smp.c:1043
 on_each_cpu_cond include/linux/smp.h:106 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1557
 kill_bdev block/bdev.c:90 [inline]
 blkdev_flush_mapping+0x9a/0x1a0 block/bdev.c:728
 blkdev_put_whole block/bdev.c:735 [inline]
 bdev_release+0x2bf/0x3d0 block/bdev.c:1160
 blkdev_release+0x15/0x20 block/fops.c:705
 __fput+0x29b/0x650 fs/file_table.c:469
 fput_close_sync+0xad/0x190 fs/file_table.c:574
 __do_sys_close fs/open.c:1509 [inline]
 __se_sys_close fs/open.c:1494 [inline]
 __x64_sys_close+0x55/0xf0 fs/open.c:1494
 x64_sys_call+0x275d/0x3020 arch/x86/include/generated/asm/syscalls_64.h:4
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff8881006093a8 -> 0xffff888100609478

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3298 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
==================================================================

Crashes (271):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/11 09:22 upstream b4f0dd314b39 86914af9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/03/09 21:55 upstream 1f318b96cc84 176bead5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/03/05 20:33 upstream c107785c7e8d d20b04c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/03/04 20:58 upstream 0031c06807cf e6b6b96b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/03/02 06:41 upstream 39c633261414 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/02/28 22:10 upstream 2f9339c052bd 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/02/26 09:43 upstream d9d32e5bd5a4 e0f78d93 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/02/24 20:38 upstream 7dff99b35460 96b1aa46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/02/23 18:18 upstream 6de23f81a5e0 6beca497 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/02/17 19:36 upstream d295082ea672 06ec4f7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/02/17 07:53 upstream 970296997869 e439b951 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/02/15 11:09 upstream ca4ee40bf13d 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/02/14 14:34 upstream 770aaedb461a 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/02/14 04:25 upstream cee73b1e840c 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/02/11 16:16 upstream 192c0159402e 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/02/09 22:55 upstream 05f7e89ab973 4ab09a02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/02/06 03:13 upstream 8fdb05de0e2d f03c4191 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/02/04 19:07 upstream 5fd0a1df5d05 ea10c935 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/02/04 02:06 upstream de0674d9bc69 42b01fab .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/02/02 00:25 upstream 9f2693489ef8 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/29 04:28 upstream 8dfce8991b95 0adc945e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/28 19:46 upstream 8dfce8991b95 004c195c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/27 17:13 upstream fcb70a56f4d8 9a514c2f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/26 14:52 upstream 63804fed149a a4c52dd6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/26 04:36 upstream 023777797472 55756628 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/25 07:13 upstream 5dbeeb268b63 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/22 07:17 upstream a66191c590b3 a16aed1d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/22 03:18 upstream cf38b2340c0e 8fc37797 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/21 07:40 upstream 6c790212c588 6f1aa2f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/20 18:27 upstream 24d479d26b25 06648d9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/19 11:16 upstream 24d479d26b25 a9fc5226 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/18 14:31 upstream d12453c7e281 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/17 00:09 upstream b62ce2547fe8 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/16 04:15 upstream 603c05a1639f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/13 10:56 upstream b71e635feefc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/10 09:20 upstream b6151c4e60e5 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/07 04:22 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2026/01/01 19:27 upstream b69053dd3ffb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2025/12/31 15:46 upstream c8ebd433459b d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2025/12/30 05:12 upstream 8640b74557fc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2025/12/29 15:31 upstream 7839932417dd d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2025/12/27 19:36 upstream c53f467229a7 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2025/12/25 00:56 upstream ccd1cdca5cd4 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2025/12/22 03:06 upstream 765b233a9b94 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
2025/04/26 16:25 upstream f1a3944c860b c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in find_get_block_common / has_bh_in_lru
* Struck through repros no longer work on HEAD.