syzbot


KCSAN: data-race in shmem_rename2 / vfs_getattr_nosec (3)

Status: auto-closed as invalid on 2022/02/15 07:51
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 322d, last: 322d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in shmem_rename2 / vfs_getattr_nosec (2) 1 421d 421d 0/24 auto-closed as invalid on 2021/11/07 14:02
upstream KCSAN: data-race in shmem_rename2 / vfs_getattr_nosec 1 645d 645d 0/24 auto-closed as invalid on 2021/05/17 11:26

Sample crash report:
==================================================================
BUG: KCSAN: data-race in shmem_rename2 / vfs_getattr_nosec

write to 0xffff888104d2cd08 of 8 bytes by task 6113 on cpu 1:
 shmem_rename2+0x229/0x2d0 mm/shmem.c:3019
 vfs_rename+0x9d9/0xe00 fs/namei.c:4626
 do_renameat2+0x6d7/0xa20 fs/namei.c:4777
 __do_sys_rename fs/namei.c:4823 [inline]
 __se_sys_rename fs/namei.c:4821 [inline]
 __x64_sys_rename+0x58/0x60 fs/namei.c:4821
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888104d2cd08 of 8 bytes by task 3654 on cpu 0:
 i_size_read include/linux/fs.h:891 [inline]
 generic_fillattr fs/stat.c:53 [inline]
 vfs_getattr_nosec+0x242/0x2f0 fs/stat.c:126
 vfs_getattr fs/stat.c:160 [inline]
 vfs_statx+0x138/0x2a0 fs/stat.c:225
 vfs_fstatat fs/stat.c:243 [inline]
 __do_sys_newfstatat fs/stat.c:412 [inline]
 __se_sys_newfstatat+0x63/0x260 fs/stat.c:406
 __x64_sys_newfstatat+0x51/0x60 fs/stat.c:406
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000001694 -> 0x00000000000016a8

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 3654 Comm: udevd Not tainted 5.16.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/01/11 07:46 upstream 133d9c53c9dc ddb0ab8c .config log report info KCSAN: data-race in shmem_rename2 / vfs_getattr_nosec
* Struck through repros no longer work on HEAD.