syzbot


KCSAN: data-race in inode_set_ctime_to_ts / inode_update_timestamps

Status: moderation: reported on 2024/12/07 03:44
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+5bb7e024098072fa0406@syzkaller.appspotmail.com
First crash: 111d, last: 41d

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

write to 0xffff888106baeee8 of 4 bytes by task 9272 on cpu 0:
 inode_set_ctime_to_ts+0x85/0x180 fs/inode.c:2716
 inode_set_ctime_current+0x1b5/0x770 fs/inode.c:2779
 inode_update_timestamps+0x85/0x250 fs/inode.c:2066
 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

read to 0xffff888106baeee8 of 4 bytes by task 9263 on cpu 1:
 inode_get_ctime_nsec include/linux/fs.h:1738 [inline]
 inode_get_ctime include/linux/fs.h:1744 [inline]
 inode_update_timestamps+0x50/0x250 fs/inode.c:2063
 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: 0x162df885 -> 0x1cbc7003

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 9263 Comm: syz.1.2620 Tainted: G        W          6.14.0-rc2-syzkaller-00185-g128c8f96eb86 #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
==================================================================

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/14 15:20 upstream 128c8f96eb86 1022af74 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in inode_set_ctime_to_ts / inode_update_timestamps
2025/01/31 19:33 upstream 69b8923f5003 aa47157c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in inode_set_ctime_to_ts / inode_update_timestamps
2025/01/25 19:56 upstream 0f8e26b38d7a 9fbd772e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in inode_set_ctime_to_ts / inode_update_timestamps
2025/01/11 23:19 upstream b62cef9a5c67 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in inode_set_ctime_to_ts / inode_update_timestamps
2024/12/07 03:44 upstream 9a6e8c7c3a02 9ac0fdc6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in inode_set_ctime_to_ts / inode_update_timestamps
* Struck through repros no longer work on HEAD.