syzbot


KCSAN: data-race in file_update_time / inode_update_timestamps (2)

Status: moderation: reported on 2024/10/07 08:11
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+c27a4f864fd990610379@syzkaller.appspotmail.com
First crash: 130d, last: 10d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in file_update_time / inode_update_timestamps ext4 34 179d 378d 0/28 auto-obsoleted due to no activity on 2024/09/23 06:59

Sample crash report:
==================================================================
BUG: KCSAN: data-race in file_update_time / inode_update_timestamps

read to 0xffff8881162fcee4 of 4 bytes by task 4299 on cpu 0:
 inode_get_mtime_nsec include/linux/fs.h:1682 [inline]
 inode_get_mtime include/linux/fs.h:1688 [inline]
 inode_needs_update_time fs/inode.c:2332 [inline]
 file_update_time+0x8b/0x2b0 fs/inode.c:2379
 pipe_write+0xa7b/0xd20 fs/pipe.c:608
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0x77b/0x920 fs/read_write.c:679
 ksys_write+0xe8/0x1b0 fs/read_write.c:731
 __do_sys_write fs/read_write.c:742 [inline]
 __se_sys_write fs/read_write.c:739 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:739
 x64_sys_call+0x287e/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff8881162fcee4 of 4 bytes by task 4296 on cpu 1:
 inode_set_mtime_to_ts include/linux/fs.h:1696 [inline]
 inode_update_timestamps+0x139/0x250 fs/inode.c:2070
 generic_update_time fs/inode.c:2105 [inline]
 inode_update_time fs/inode.c:2125 [inline]
 __file_update_time fs/inode.c:2353 [inline]
 file_update_time+0x219/0x2b0 fs/inode.c:2383
 pipe_write+0xa7b/0xd20 fs/pipe.c:608
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0x77b/0x920 fs/read_write.c:679
 ksys_write+0xe8/0x1b0 fs/read_write.c:731
 __do_sys_write fs/read_write.c:742 [inline]
 __se_sys_write fs/read_write.c:739 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:739
 x64_sys_call+0x287e/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0dff0320 -> 0x1b7db898

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 4296 Comm: syz.2.270 Not tainted 6.14.0-rc1-syzkaller-00020-g0de63bb7d919 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
==================================================================

Crashes (12):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/04 04:05 upstream 0de63bb7d919 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in file_update_time / inode_update_timestamps
2025/01/13 16:50 upstream 5bc55a333a2f 249ceea9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in file_update_time / inode_update_timestamps
2025/01/11 01:05 upstream 2144da25584e 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in file_update_time / inode_update_timestamps
2025/01/02 06:47 upstream 56e6a3499e14 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in file_update_time / inode_update_timestamps
2024/12/04 15:42 upstream feffde684ac2 b50eb251 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in file_update_time / inode_update_timestamps
2024/11/08 11:47 upstream 906bd684e4b1 179b040e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in file_update_time / inode_update_timestamps
2024/11/07 19:35 upstream ff7afaeca1a1 867e44df .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in file_update_time / inode_update_timestamps
2024/10/18 07:05 upstream 6efbea77b390 666f77ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in file_update_time / inode_update_timestamps
2024/10/08 18:16 upstream 87d6aab2389e 402f1df0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in file_update_time / inode_update_timestamps
2024/10/08 02:58 upstream 87d6aab2389e d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in file_update_time / inode_update_timestamps
2024/10/08 02:55 upstream 87d6aab2389e d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in file_update_time / inode_update_timestamps
2024/10/07 08:10 upstream 8cf0b93919e1 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in file_update_time / inode_update_timestamps
* Struck through repros no longer work on HEAD.