syzbot


KCSAN: data-race in ext4_setattr / generic_fillattr

Status: auto-closed as invalid on 2021/12/03 16:13
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 394d, last: 394d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_setattr / generic_fillattr

write to 0xffff888104bea590 of 4 bytes by task 31104 on cpu 0:
 ext4_setattr+0x567/0xef0 fs/ext4/inode.c:5344
 notify_change+0x8a3/0xac0 fs/attr.c:410
 chown_common+0x25e/0x390 fs/open.c:678
 do_fchownat+0x104/0x1a0 fs/open.c:709
 __do_sys_lchown fs/open.c:734 [inline]
 __se_sys_lchown fs/open.c:732 [inline]
 __x64_sys_lchown+0x46/0x50 fs/open.c:732
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888104bea590 of 4 bytes by task 31105 on cpu 1:
 i_gid_into_mnt include/linux/fs.h:1682 [inline]
 generic_fillattr+0xb2/0x190 fs/stat.c:51
 ext4_getattr+0x2c4/0x2e0 fs/ext4/inode.c:5531
 vfs_getattr_nosec+0x153/0x2f0 fs/stat.c:123
 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+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffffff00 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 31105 Comm: syz-executor.2 Not tainted 5.15.0-rc7-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 2021/10/29 16:04 upstream f25a5481af12 2353a3ec .config log report info KCSAN: data-race in ext4_setattr / generic_fillattr
* Struck through repros no longer work on HEAD.