syzbot


KCSAN: data-race in generic_fillattr / shmem_symlink (3)

Status: moderation: reported on 2024/06/27 09:17
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+e4b2def43a75c1357c73@syzkaller.appspotmail.com
First crash: 16d, last: 1d01h
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in generic_fillattr / shmem_symlink (2) mm 247 79d 219d 0/27 auto-obsoleted due to no activity on 2024/05/30 03:00
upstream KCSAN: data-race in generic_fillattr / shmem_symlink fs 30 1490d 1680d 0/27 closed as invalid on 2020/06/18 14:24

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

write to 0xffff88810444aff0 of 8 bytes by task 4287 on cpu 0:
 inode_set_mtime_to_ts include/linux/fs.h:1587 [inline]
 shmem_symlink+0x349/0x3a0 mm/shmem.c:3551
 vfs_symlink+0xca/0x1d0 fs/namei.c:4495
 do_symlinkat+0xe3/0x350 fs/namei.c:4521
 __do_sys_symlink fs/namei.c:4542 [inline]
 __se_sys_symlink fs/namei.c:4540 [inline]
 __x64_sys_symlink+0x56/0x70 fs/namei.c:4540
 x64_sys_call+0x14d2/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:89
 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 0xffff88810444aff0 of 8 bytes by task 3300 on cpu 1:
 inode_get_mtime include/linux/fs.h:1581 [inline]
 generic_fillattr+0x1a6/0x2f0 fs/stat.c:61
 shmem_getattr+0x17b/0x200 mm/shmem.c:1150
 vfs_getattr_nosec fs/stat.c:135 [inline]
 vfs_getattr+0x19b/0x1e0 fs/stat.c:176
 vfs_statx+0x140/0x320 fs/stat.c:248
 vfs_fstatat+0xcd/0x100 fs/stat.c:304
 __do_sys_newfstatat fs/stat.c:468 [inline]
 __se_sys_newfstatat+0x58/0x260 fs/stat.c:462
 __x64_sys_newfstatat+0x55/0x70 fs/stat.c:462
 x64_sys_call+0x1451/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:263
 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: 0x000000001be32f0f -> 0x000000001ed5c86d

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3300 Comm: udevd Not tainted 6.10.0-rc7-syzkaller-00141-g43db1e03c086 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
==================================================================

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/07/12 09:51 upstream 43db1e03c086 eaeb5c15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in generic_fillattr / shmem_symlink
2024/07/09 12:11 upstream 4376e966ecb7 bc23a442 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in generic_fillattr / shmem_symlink
2024/07/06 15:04 upstream 1dd28064d416 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in generic_fillattr / shmem_symlink
2024/06/27 09:17 upstream afcd48134c58 6ef39602 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in generic_fillattr / shmem_symlink
* Struck through repros no longer work on HEAD.