syzbot


KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set (4)

Status: closed as invalid on 2022/05/13 11:20
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 200d, last: 200d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set 1876 342d 1141d 0/24 auto-closed as invalid on 2022/01/25 08:41
upstream KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set (3) 54 200d 202d 0/24 closed as invalid on 2022/05/12 12:04
upstream KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set (2) 6 297d 299d 0/24 auto-closed as invalid on 2022/03/10 19:17

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set

write to 0xffff888103c8f00e of 2 bytes by task 13093 on cpu 1:
 ext4_free_inodes_set+0x1b/0x80 fs/ext4/super.c:403
 ext4_free_inode+0x42d/0x810 fs/ext4/ialloc.c:323
 ext4_evict_inode+0xbd7/0xe40 fs/ext4/inode.c:331
 evict+0x1aa/0x410 fs/inode.c:664
 iput_final fs/inode.c:1744 [inline]
 iput+0x3f9/0x580 fs/inode.c:1770
 do_unlinkat+0x2b3/0x510 fs/namei.c:4223
 __do_sys_unlink fs/namei.c:4264 [inline]
 __se_sys_unlink fs/namei.c:4262 [inline]
 __x64_sys_unlink+0x2c/0x30 fs/namei.c:4262
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888103c8f00e of 2 bytes by task 1822 on cpu 0:
 ext4_free_inodes_count+0x18/0x80 fs/ext4/super.c:347
 find_group_orlov+0x7b6/0x830 fs/ext4/ialloc.c:505
 __ext4_new_inode+0x990/0x2700
 ext4_mkdir+0x287/0x760 fs/ext4/namei.c:2929
 vfs_mkdir+0x216/0x320 fs/namei.c:3931
 do_mkdirat+0x105/0x280 fs/namei.c:3957
 __do_sys_mkdirat fs/namei.c:3972 [inline]
 __se_sys_mkdirat fs/namei.c:3970 [inline]
 __x64_sys_mkdirat+0x4c/0x60 fs/namei.c:3970
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x1b6f -> 0x1b70

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1822 Comm: syz-executor.4 Not tainted 5.18.0-rc6-syzkaller-00009-gfeb9c5e19e91 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/05/12 13:24 upstream feb9c5e19e91 9ad6612a .config log report info KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set
ci2-upstream-kcsan-gce 2022/05/12 13:20 upstream feb9c5e19e91 9ad6612a .config log report info KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set
* Struck through repros no longer work on HEAD.