syzbot


KCSAN: data-race in bdev_statx / queue_limits_commit_update (2)

Status: moderation: reported on 2025/07/05 22:43
Subsystems: block
[Documentation on labels]
Reported-by: syzbot+b3987a634290a5f1bd78@syzkaller.appspotmail.com
First crash: 121d, last: 6d05h
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in bdev_statx / queue_limits_commit_update block 6 1 179d 179d 0/29 auto-obsoleted due to no activity on 2025/07/03 18:51

Sample crash report:
==================================================================
BUG: KCSAN: data-race in bdev_statx / queue_limits_commit_update

read to 0xffff888102308c28 of 4 bytes by task 3497 on cpu 1:
 queue_io_min include/linux/blkdev.h:1387 [inline]
 bdev_io_min include/linux/blkdev.h:1392 [inline]
 bdev_statx+0x295/0x2d0 block/bdev.c:1342
 vfs_getattr_nosec+0x1b6/0x1e0 fs/stat.c:227
 vfs_getattr fs/stat.c:262 [inline]
 vfs_fstat fs/stat.c:281 [inline]
 __do_sys_newfstat fs/stat.c:555 [inline]
 __se_sys_newfstat+0x96/0x2e0 fs/stat.c:550
 __x64_sys_newfstat+0x31/0x40 fs/stat.c:550
 x64_sys_call+0x2768/0x3000 arch/x86/include/generated/asm/syscalls_64.h:6
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff888102308be8 of 192 bytes by task 9349 on cpu 0:
 queue_limits_commit_update+0x4b/0x160 block/blk-settings.c:550
 loop_configure+0x78c/0x9c0 drivers/block/loop.c:1066
 lo_ioctl+0x1e1/0x12b0 drivers/block/loop.c:1536
 blkdev_ioctl+0x356/0x440 block/ioctl.c:705
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xce/0x140 fs/ioctl.c:583
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583
 x64_sys_call+0x1816/0x3000 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 9349 Comm: syz.3.1656 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
==================================================================
loop3: detected capacity change from 0 to 512
EXT4-fs (loop3): encrypted files will use data=ordered instead of data journaling mode
EXT4-fs (loop3): 1 truncate cleaned up
EXT4-fs (loop3): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/29 06:31 upstream 8eefed8f65cc fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in bdev_statx / queue_limits_commit_update
2025/10/07 07:59 upstream c746c3b51698 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in bdev_statx / queue_limits_commit_update
2025/10/01 00:41 upstream 30d4efb2f5a5 65a0eece .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in bdev_statx / queue_limits_commit_update
2025/09/21 05:10 upstream 3b08f56fbbb9 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in bdev_statx / queue_limits_commit_update
2025/09/20 13:07 upstream cd89d487374c 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in bdev_statx / queue_limits_commit_update
2025/09/10 20:21 upstream 7aac71907bde fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in bdev_statx / queue_limits_commit_update
2025/08/03 05:33 upstream 186f3edfdd41 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in bdev_statx / queue_limits_commit_update
2025/07/27 10:48 upstream ec2df4364666 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in bdev_statx / queue_limits_commit_update
2025/07/23 01:50 upstream 89be9a83ccf1 8e9d1dc1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in bdev_statx / queue_limits_commit_update
2025/07/05 22:43 upstream 05df91921da6 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in bdev_statx / queue_limits_commit_update
* Struck through repros no longer work on HEAD.