syzbot


KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set (2)

Status: auto-closed as invalid on 2022/03/10 19:17
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 304d, last: 302d
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 (4) 2 205d 205d 0/24 closed as invalid on 2022/05/13 11:20
upstream KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set 1876 347d 1146d 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 205d 207d 0/24 closed as invalid on 2022/05/12 12:04

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

write to 0xffff8881037e800e of 2 bytes by task 1826 on cpu 1:
 ext4_free_inodes_set+0x1b/0x80 fs/ext4/super.c:403
 ext4_free_inode+0x615/0xa30 fs/ext4/ialloc.c:323
 ext4_evict_inode+0xbff/0xf10 fs/ext4/inode.c:333
 evict+0x1aa/0x410 fs/inode.c:664
 iput_final fs/inode.c:1744 [inline]
 iput+0x3ef/0x580 fs/inode.c:1770
 do_unlinkat+0x2d4/0x540 fs/namei.c:4225
 __do_sys_unlink fs/namei.c:4266 [inline]
 __se_sys_unlink fs/namei.c:4264 [inline]
 __x64_sys_unlink+0x2c/0x30 fs/namei.c:4264
 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 0xffff8881037e800e of 2 bytes by task 15715 on cpu 0:
 ext4_free_inodes_count+0x18/0x80 fs/ext4/super.c:347
 __ext4_new_inode+0x959/0x30b0 fs/ext4/ialloc.c:1042
 ext4_symlink+0x2cc/0x700 fs/ext4/namei.c:3293
 vfs_symlink+0x18a/0x280 fs/namei.c:4299
 do_symlinkat+0x104/0x380 fs/namei.c:4328
 __do_sys_symlink fs/namei.c:4350 [inline]
 __se_sys_symlink fs/namei.c:4348 [inline]
 __x64_sys_symlink+0x52/0x60 fs/namei.c:4348
 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: 0x1b5b -> 0x1b5c

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15715 Comm: syz-executor.5 Not tainted 5.17.0-rc2-syzkaller-00064-gc36c04c2e132 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (6):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/02/03 19:14 upstream c36c04c2e132 30646bfe .config log report info KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set
ci2-upstream-kcsan-gce 2022/02/03 07:52 upstream 88808fbbead4 4ebb2798 .config log report info KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set
ci2-upstream-kcsan-gce 2022/02/02 18:24 upstream 27bb0b18c208 4ebb2798 .config log report info KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set
ci2-upstream-kcsan-gce 2022/02/01 22:34 upstream 9f7fb8de5d9b 4ebb2798 .config log report info KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set
ci2-upstream-kcsan-gce 2022/02/01 21:14 upstream 9f7fb8de5d9b c1c1631d .config log report info KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set
ci2-upstream-kcsan-gce 2022/02/01 21:14 upstream 9f7fb8de5d9b c1c1631d .config log report info KCSAN: data-race in ext4_free_inodes_count / ext4_free_inodes_set
* Struck through repros no longer work on HEAD.