syzbot


KCSAN: data-race in fill_mg_cmtime / shmem_mknod

Status: moderation: reported on 2024/11/20 08:18
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+9195e9356af82aebbf9f@syzkaller.appspotmail.com
First crash: 240d, last: 8h38m

Sample crash report:
==================================================================
BUG: KCSAN: data-race in fill_mg_cmtime / shmem_mknod

write to 0xffff88810421c3dc of 4 bytes by task 3551 on cpu 0:
 inode_set_mtime_to_ts include/linux/fs.h:1718 [inline]
 shmem_mknod+0x137/0x180 mm/shmem.c:3861
 shmem_create+0x34/0x50 mm/shmem.c:3920
 lookup_open fs/namei.c:3717 [inline]
 open_last_lookups fs/namei.c:3816 [inline]
 path_openat+0x1102/0x2170 fs/namei.c:4052
 do_filp_open+0x109/0x230 fs/namei.c:4082
 do_sys_openat2+0xa6/0x110 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1463
 x64_sys_call+0x1af/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:258
 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

read to 0xffff88810421c3dc of 4 bytes by task 3550 on cpu 1:
 inode_get_mtime_nsec include/linux/fs.h:1704 [inline]
 inode_get_mtime include/linux/fs.h:1710 [inline]
 fill_mg_cmtime+0x5b/0x260 fs/stat.c:55
 generic_fillattr+0x24a/0x340 fs/stat.c:99
 shmem_getattr+0x181/0x200 mm/shmem.c:1262
 vfs_getattr_nosec+0x143/0x1e0 fs/stat.c:213
 vfs_getattr fs/stat.c:262 [inline]
 vfs_statx_path fs/stat.c:299 [inline]
 vfs_statx+0x113/0x390 fs/stat.c:356
 vfs_fstatat+0x115/0x170 fs/stat.c:375
 __do_sys_newfstatat fs/stat.c:542 [inline]
 __se_sys_newfstatat+0x55/0x260 fs/stat.c:536
 __x64_sys_newfstatat+0x55/0x70 fs/stat.c:536
 x64_sys_call+0x2c22/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:263
 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

value changed: 0x3a52ecef -> 0x3adca135

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3550 Comm: udevd Not tainted 6.16.0-rc6-syzkaller-00121-g6832a9317eee #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================
udevd[3550]: inotify_add_watch(7, /dev/loop3p1, 10) failed: No such file or directory
udevd[3550]: inotify_add_watch(7, /dev/loop4p1, 10) failed: No such file or directory
udevd[3550]: inotify_add_watch(7, /dev/loop4p1, 10) failed: No such file or directory

Crashes (268):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/18 09:03 upstream 6832a9317eee 88248e14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/07/17 20:19 upstream e2291551827f 0d1223f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/07/17 02:25 upstream e2291551827f 44f8051e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/07/15 08:52 upstream 155a3c003e55 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/07/13 22:59 upstream 5d5d62298b8b 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/07/11 19:25 upstream 40f92e79b0aa 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/07/11 10:41 upstream bc9ff192a6c9 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/07/09 14:59 upstream 733923397fd9 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/07/07 07:37 upstream d7b8f8e20813 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/07/05 21:43 upstream 05df91921da6 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/07/02 12:57 upstream 66701750d556 bc80e4f0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/07/01 17:44 upstream 66701750d556 091a06cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/07/01 04:16 upstream 66701750d556 6e83b42d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/30 17:15 upstream d0b3b7b22dfa 6e83b42d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/30 03:35 upstream d0b3b7b22dfa fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/29 13:28 upstream dfba48a70cb6 fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/29 02:55 upstream ded779017ad7 fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/25 09:01 upstream 7595b66ae9de 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/24 05:54 upstream 78f4e737a53e e2f27c35 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/22 05:58 upstream 739a6c93cc75 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/21 09:17 upstream 11313e2f7812 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/20 07:09 upstream 75f5f23f8787 ed3e87f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/19 17:46 upstream 24770983ccfe ed3e87f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/19 07:17 upstream fb4d33ab452e ed3e87f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/18 08:53 upstream 52da431bf03b e77fae15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/17 19:13 upstream 4663747812d1 cfebc887 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/16 16:27 upstream e04c78d86a96 d1716036 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/12 01:55 upstream 488ef3560196 98683f8f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/09 08:35 upstream 19272b37aa4f 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/08 19:49 upstream 939f15e640f1 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/05 13:39 upstream ec7714e49479 6b6b5f21 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/04 17:13 upstream 1af80d00e1e0 e565f08d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/04 15:40 upstream 5abc7438f1e9 e565f08d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/03 05:28 upstream fe4281644c62 a30356b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/06/02 10:52 upstream cd2e103d57e5 b396b4bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/28 07:34 upstream feacb1774bd5 874a1386 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/25 01:02 upstream b1427432d3b6 ed351ea7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/22 09:33 upstream d608703fcdd9 0919b50b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/21 01:20 upstream b36ddb9210e6 b47f9e02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/20 11:24 upstream a5806cd506af b47f9e02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/19 11:21 upstream a5806cd506af b84f0537 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/19 00:53 upstream a5806cd506af f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/16 21:22 upstream 3c21441eeffc f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/16 18:44 upstream 3c21441eeffc cfde8269 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/14 09:58 upstream 9f35e33144ae 7344edeb .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/13 15:24 upstream e9565e23cd89 7344edeb .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/10 22:28 upstream bec6f00f120e 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/09 11:55 upstream 2c89c1b655c0 bb813bcc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/06 17:13 upstream 0d8d44db295c ae98e6b9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2024/11/20 08:17 upstream bf9aa14fc523 7d02db5a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
* Struck through repros no longer work on HEAD.