syzbot


KCSAN: data-race in drop_nlink / generic_fillattr (7)

Status: auto-obsoleted due to no activity on 2024/04/11 18:19
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+36c620456f1103f87b6a@syzkaller.appspotmail.com
First crash: 113d, last: 107d
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in drop_nlink / generic_fillattr (4) fs 2 479d 522d 0/27 auto-obsoleted due to no activity on 2023/04/11 17:00
upstream KCSAN: data-race in drop_nlink / generic_fillattr (6) fs 2 149d 156d 0/27 auto-obsoleted due to no activity on 2024/02/29 22:16
upstream KCSAN: data-race in drop_nlink / generic_fillattr (5) fs 2 226d 195d 0/27 auto-obsoleted due to no activity on 2023/12/25 00:01
upstream KCSAN: data-race in drop_nlink / generic_fillattr (3) fs 22 984d 1195d 0/27 auto-closed as invalid on 2021/11/16 10:39
upstream KCSAN: data-race in drop_nlink / generic_fillattr fs 9 1375d 1450d 0/27 auto-closed as invalid on 2020/10/22 03:32
upstream KCSAN: data-race in drop_nlink / generic_fillattr (2) fs 8 1249d 1293d 0/27 auto-closed as invalid on 2021/02/25 00:13

Sample crash report:
==================================================================
BUG: KCSAN: data-race in drop_nlink / generic_fillattr

write to 0xffff888122f40f78 of 4 bytes by task 9409 on cpu 0:
 drop_nlink+0x3b/0x90 fs/inode.c:332
 shmem_unlink+0x169/0x180 mm/shmem.c:3370
 shmem_rename2+0x1dc/0x2c0 mm/shmem.c:3449
 vfs_rename+0x867/0x9c0 fs/namei.c:4883
 do_renameat2+0x732/0xa60 fs/namei.c:5040
 __do_sys_rename fs/namei.c:5087 [inline]
 __se_sys_rename fs/namei.c:5085 [inline]
 __x64_sys_rename+0x5c/0x70 fs/namei.c:5085
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888122f40f78 of 4 bytes by task 2773 on cpu 1:
 generic_fillattr+0xf8/0x2f0 fs/stat.c:55
 shmem_getattr+0x17b/0x200 mm/shmem.c:1139
 vfs_getattr_nosec fs/stat.c:135 [inline]
 vfs_getattr fs/stat.c:176 [inline]
 vfs_fstat+0x1b5/0x460 fs/stat.c:198
 vfs_fstatat+0x85/0x100 fs/stat.c:300
 __do_sys_newfstatat fs/stat.c:468 [inline]
 __se_sys_newfstatat+0x58/0x260 fs/stat.c:462
 __x64_sys_newfstatat+0x55/0x60 fs/stat.c:462
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x00000001 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 2773 Comm: udevd Not tainted 6.8.0-rc7-syzkaller-00130-g135288b73cef #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/07 18:18 upstream 135288b73cef 2b789849 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in drop_nlink / generic_fillattr
2024/03/01 15:18 upstream 87adedeba51a 83acf9e0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in drop_nlink / generic_fillattr
* Struck through repros no longer work on HEAD.