syzbot


possible deadlock in reiserfs_ioctl

Status: upstream: reported C repro on 2022/11/11 18:26
Reported-by: syzbot+79c303ad05f4041e0dad@syzkaller.appspotmail.com
First crash: 23d, last: 12h51m

Cause bisection: failed (bisect log)

Sample crash report:
REISERFS (device loop0): checking transaction log (loop0)
REISERFS (device loop0): Using rupasov hash to sort names
REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage.
======================================================
WARNING: possible circular locking dependency detected
6.1.0-rc3-next-20221104-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor418/5242 is trying to acquire lock:
ffff8880289b2460 (sb_writers#9){.+.+}-{0:0}, at: reiserfs_ioctl+0x19e/0x320 fs/reiserfs/ioctl.c:103

but task is already holding lock:
ffff888016eec090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xf0 fs/reiserfs/lock.c:27

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&sbi->lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747
       reiserfs_write_lock+0x75/0xf0 fs/reiserfs/lock.c:27
       reiserfs_lookup+0x171/0x490 fs/reiserfs/namei.c:364
       __lookup_slow+0x24c/0x460 fs/namei.c:1685
       lookup_one_len+0x16a/0x1a0 fs/namei.c:2711
       reiserfs_lookup_privroot+0x92/0x280 fs/reiserfs/xattr.c:973
       reiserfs_fill_super+0x20e5/0x2e90 fs/reiserfs/super.c:2174
       mount_bdev+0x34d/0x410 fs/super.c:1401
       legacy_get_tree+0x105/0x220 fs/fs_context.c:610
       vfs_get_tree+0x89/0x2f0 fs/super.c:1531
       do_new_mount fs/namespace.c:3145 [inline]
       path_mount+0x1326/0x1e20 fs/namespace.c:3475
       do_mount fs/namespace.c:3488 [inline]
       __do_sys_mount fs/namespace.c:3696 [inline]
       __se_sys_mount fs/namespace.c:3673 [inline]
       __x64_sys_mount+0x27f/0x300 fs/namespace.c:3673
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #1 (&type->i_mutex_dir_key#6){+.+.}-{3:3}:
       down_write+0x90/0x220 kernel/locking/rwsem.c:1562
       inode_lock include/linux/fs.h:756 [inline]
       chmod_common+0x14b/0x410 fs/open.c:600
       vfs_fchmod fs/open.c:622 [inline]
       __do_sys_fchmod fs/open.c:631 [inline]
       __se_sys_fchmod fs/open.c:625 [inline]
       __x64_sys_fchmod+0x10e/0x190 fs/open.c:625
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (sb_writers#9){.+.+}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3097 [inline]
       check_prevs_add kernel/locking/lockdep.c:3216 [inline]
       validate_chain kernel/locking/lockdep.c:3831 [inline]
       __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055
       lock_acquire kernel/locking/lockdep.c:5668 [inline]
       lock_acquire+0x1df/0x630 kernel/locking/lockdep.c:5633
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1792 [inline]
       sb_start_write include/linux/fs.h:1867 [inline]
       mnt_want_write_file+0x8e/0x590 fs/namespace.c:552
       reiserfs_ioctl+0x19e/0x320 fs/reiserfs/ioctl.c:103
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl fs/ioctl.c:856 [inline]
       __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Chain exists of:
  sb_writers#9 --> &type->i_mutex_dir_key#6 --> &sbi->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sbi->lock);
                               lock(&type->i_mutex_dir_key#6);
                               lock(&sbi->lock);
  lock(sb_writers#9);

 *** DEADLOCK ***

1 lock held by syz-executor418/5242:
 #0: ffff888016eec090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xf0 fs/reiserfs/lock.c:27

stack backtrace:
CPU: 1 PID: 5242 Comm: syz-executor418 Not tainted 6.1.0-rc3-next-20221104-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2177
 check_prev_add kernel/locking/lockdep.c:3097 [inline]
 check_prevs_add kernel/locking/lockdep.c:3216 [inline]
 validate_chain kernel/locking/lockdep.c:3831 [inline]
 __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055
 lock_acquire kernel/locking/lockdep.c:5668 [inline]
 lock_acquire+0x1df/0x630 kernel/locking/lockdep.c:5633
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1792 [inline]
 sb_start_write include/linux/fs.h:1867 [inline]
 mnt_want_write_file+0x8e/0x590 fs/namespace.c:552
 reiserfs_ioctl+0x19e/0x320 fs/reiserfs/ioctl.c:103
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f157998c889
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe2dd23488 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f157998c889
RDX: 0000000000000000 RSI: 0000000040087602 RDI: 0000000000000005
RBP: 0000000000000000 R08: 00007f15799faec0 R09: 00007f15799faec0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe2dd234b0
R13: 0000000000000000 R14: 431bde82d7b634db R15: 0000000000000000
 </TASK>

Crashes (18):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-linux-next-kasan-gce-root 2022/11/10 13:06 linux-next 0cdb3579f1ee b2488a87 .config log report syz C possible deadlock in reiserfs_ioctl
ci-upstream-kasan-gce-selinux-root 2022/12/03 04:02 upstream a4412fdd49dc e080de16 .config log report info possible deadlock in reiserfs_ioctl
ci-upstream-kasan-gce-root 2022/12/02 08:13 upstream ef4d3ea40565 e080de16 .config log report info possible deadlock in reiserfs_ioctl
ci-upstream-kasan-gce-root 2022/11/30 17:48 upstream 01f856ae6d0c 4c2a66e8 .config log report info possible deadlock in reiserfs_ioctl
ci-upstream-kasan-gce-root 2022/11/30 17:29 upstream 01f856ae6d0c 4c2a66e8 .config log report info possible deadlock in reiserfs_ioctl
ci-qemu-upstream 2022/11/28 04:26 upstream bf82d38c91f8 f4470a7b .config log report info possible deadlock in reiserfs_ioctl
ci-upstream-kasan-gce-root 2022/11/27 06:26 upstream 644e9524388a 74a66371 .config log report info possible deadlock in reiserfs_ioctl
ci-upstream-kasan-gce-root 2022/11/23 13:33 upstream eb7081409f94 75740b3f .config log report info possible deadlock in reiserfs_ioctl
ci-upstream-kasan-gce-selinux-root 2022/11/23 04:50 upstream eb7081409f94 9da37ae8 .config log report info possible deadlock in reiserfs_ioctl
ci-upstream-kasan-gce-root 2022/11/23 02:34 upstream eb7081409f94 9da37ae8 .config log report info possible deadlock in reiserfs_ioctl
ci-upstream-kasan-gce-selinux-root 2022/11/21 23:20 upstream eb7081409f94 1c576c23 .config log report info possible deadlock in reiserfs_ioctl
ci-upstream-kasan-gce-root 2022/11/21 22:01 upstream eb7081409f94 1c576c23 .config log report info possible deadlock in reiserfs_ioctl
ci-upstream-kasan-gce-root 2022/11/20 00:29 upstream fe24a97cf254 5bb70014 .config log report info possible deadlock in reiserfs_ioctl
ci-qemu-upstream-386 2022/11/30 02:20 upstream 01f856ae6d0c 579a3740 .config log report info possible deadlock in reiserfs_ioctl
ci-qemu-upstream-386 2022/11/28 17:31 upstream b7b275e60bcd 950c3e02 .config log report info possible deadlock in reiserfs_ioctl
ci-upstream-linux-next-kasan-gce-root 2022/11/26 19:48 linux-next 9e46a7996732 74a66371 .config log report info possible deadlock in reiserfs_ioctl
ci-upstream-linux-next-kasan-gce-root 2022/11/26 17:58 linux-next 9e46a7996732 74a66371 .config log report info possible deadlock in reiserfs_ioctl
ci-upstream-linux-next-kasan-gce-root 2022/11/26 17:39 linux-next 9e46a7996732 74a66371 .config log report info possible deadlock in reiserfs_ioctl
* Struck through repros no longer work on HEAD.