syzbot


KCSAN: data-race in setattr_copy / vfs_write (3)

Status: auto-closed as invalid on 2022/03/14 15:19
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 294d, last: 294d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in setattr_copy / vfs_write 1 590d 590d 0/24 auto-closed as invalid on 2021/05/23 06:39
upstream KCSAN: data-race in setattr_copy / vfs_write (2) 1 524d 524d 0/24 auto-closed as invalid on 2021/07/27 10:55

Sample crash report:
==================================================================
BUG: KCSAN: data-race in setattr_copy / vfs_write

write to 0xffff8881357171d8 of 2 bytes by task 22342 on cpu 1:
 setattr_copy+0x238/0x250 fs/attr.c:247
 ext4_setattr+0x258/0xb30 fs/ext4/inode.c:5467
 notify_change+0x924/0xbf0 fs/attr.c:410
 chmod_common+0x13c/0x270 fs/open.c:582
 do_fchmodat fs/open.c:621 [inline]
 __do_sys_chmod fs/open.c:639 [inline]
 __se_sys_chmod fs/open.c:637 [inline]
 __x64_sys_chmod+0x9b/0x120 fs/open.c:637
 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 0xffff8881357171d8 of 2 bytes by task 22331 on cpu 0:
 fsnotify_parent include/linux/fsnotify.h:65 [inline]
 fsnotify_file include/linux/fsnotify.h:99 [inline]
 fsnotify_modify include/linux/fsnotify.h:317 [inline]
 vfs_write+0x34b/0x950 fs/read_write.c:594
 ksys_write+0xd9/0x190 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:652
 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: 0x8080 -> 0x8021

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 22331 Comm: syz-executor.5 Not tainted 5.17.0-rc3-syzkaller-dirty #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 2022/02/07 15:10 upstream dfd42facf1e4 a7dab638 .config log report info KCSAN: data-race in setattr_copy / vfs_write
* Struck through repros no longer work on HEAD.