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: 205d, last: 2d05h

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

write to 0xffff88810402cc94 of 4 bytes by task 3858 on cpu 0:
 inode_set_mtime_to_ts include/linux/fs.h:1716 [inline]
 shmem_mknod+0x137/0x180 mm/shmem.c:3857
 shmem_create+0x34/0x50 mm/shmem.c:3916
 lookup_open fs/namei.c:3708 [inline]
 open_last_lookups fs/namei.c:3807 [inline]
 path_openat+0x1102/0x2170 fs/namei.c:4043
 do_filp_open+0x109/0x230 fs/namei.c:4073
 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 0xffff88810402cc94 of 4 bytes by task 3857 on cpu 1:
 inode_get_mtime_nsec include/linux/fs.h:1702 [inline]
 inode_get_mtime include/linux/fs.h:1708 [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: 0x3051777c -> 0x3056bb78

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3857 Comm: udevd Not tainted 6.16.0-rc1-syzkaller-00005-g488ef3560196 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================

Crashes (241):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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
2025/05/06 03:03 upstream 01f95500a162 ae98e6b9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/05 19:43 upstream 01f95500a162 6ca47dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/03 20:34 upstream 2a239ffbebb5 b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/03 08:40 upstream 95d3481af6dc b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/02 16:09 upstream ebd297a2affa b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/05/01 10:14 upstream 4f79eaa2ceac ce7952f4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/04/30 20:49 upstream 7a13c14ee59d ce7952f4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/04/30 14:55 upstream ca91b9500108 85a5a23f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/04/29 16:32 upstream ca91b9500108 aeb6ec69 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/04/28 17:54 upstream f15d97df5afa c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/04/28 12:34 upstream b4432656b36e c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/04/26 21:18 upstream 5bc1018675ec c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/04/26 01:24 upstream 02ddfb981de8 c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/04/25 04:53 upstream 02ddfb981de8 e3715315 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/04/24 17:42 upstream e72e9e693307 9882047a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/04/22 21:14 upstream bc3372351d0c 53a8b9bd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/04/22 19:37 upstream a33b5a08cbbd 53a8b9bd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/04/22 04:48 upstream a33b5a08cbbd 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/04/21 11:03 upstream 9d7a0577c9db 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fill_mg_cmtime / shmem_mknod
2025/04/20 04:47 upstream 119009db2674 2a20f901 .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.