syzbot


possible deadlock in reiserfs_get_block

Status: upstream: reported on 2022/12/23 16:13
Subsystems: reiserfs (incorrect?)
Reported-by: syzbot+8a4c84020c63609f15ec@syzkaller.appspotmail.com
First crash: 93d, last: 59d

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.2.0-rc5-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.2/20096 is trying to acquire lock:
ffff88807e3435d8 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x8f/0x110 mm/memory.c:5646

but task is already holding lock:
ffff88802a6e3090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x77/0xd0 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}:
       lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
       __mutex_lock_common+0x1bd/0x26e0 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
       reiserfs_write_lock+0x77/0xd0 fs/reiserfs/lock.c:27
       reiserfs_get_block+0x24e/0x5180 fs/reiserfs/inode.c:680
       do_mpage_readpage+0x970/0x1c50 fs/mpage.c:208
       mpage_readahead+0x210/0x380 fs/mpage.c:361
       read_pages+0x169/0x9c0 mm/readahead.c:161
       page_cache_ra_unbounded+0x703/0x820 mm/readahead.c:270
       do_sync_mmap_readahead+0x4b2/0x9a0
       filemap_fault+0x38d/0x1060 mm/filemap.c:3154
       __do_fault+0x136/0x4f0 mm/memory.c:4163
       do_read_fault mm/memory.c:4514 [inline]
       do_fault mm/memory.c:4643 [inline]
       handle_pte_fault mm/memory.c:4931 [inline]
       __handle_mm_fault mm/memory.c:5073 [inline]
       handle_mm_fault+0x2066/0x26b0 mm/memory.c:5219
       faultin_page mm/gup.c:926 [inline]
       __get_user_pages+0x52b/0x1270 mm/gup.c:1153
       populate_vma_page_range+0x216/0x2b0 mm/gup.c:1526
       __mm_populate+0x2ad/0x460 mm/gup.c:1640
       mm_populate include/linux/mm.h:2874 [inline]
       vm_mmap_pgoff+0x200/0x2b0 mm/util.c:525
       ksys_mmap_pgoff+0x48c/0x6d0 mm/mmap.c:1457
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #1 (mapping.invalidate_lock#11){.+.+}-{3:3}:
       lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
       down_read+0x39/0x50 kernel/locking/rwsem.c:1509
       filemap_invalidate_lock_shared include/linux/fs.h:811 [inline]
       filemap_fault+0x2fb/0x1060 mm/filemap.c:3146
       __do_fault+0x136/0x4f0 mm/memory.c:4163
       do_shared_fault mm/memory.c:4569 [inline]
       do_fault mm/memory.c:4647 [inline]
       handle_pte_fault mm/memory.c:4931 [inline]
       __handle_mm_fault mm/memory.c:5073 [inline]
       handle_mm_fault+0x18bc/0x26b0 mm/memory.c:5219
       do_user_addr_fault+0x69b/0xcb0 arch/x86/mm/fault.c:1428
       handle_page_fault arch/x86/mm/fault.c:1519 [inline]
       exc_page_fault+0x7a/0x110 arch/x86/mm/fault.c:1575
       asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570

-> #0 (&mm->mmap_lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3097 [inline]
       check_prevs_add kernel/locking/lockdep.c:3216 [inline]
       validate_chain+0x1898/0x6ae0 kernel/locking/lockdep.c:3831
       __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
       lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
       __might_fault+0xb2/0x110 mm/memory.c:5647
       reiserfs_ioctl+0x11c/0x340 fs/reiserfs/ioctl.c:96
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/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:
  &mm->mmap_lock --> mapping.invalidate_lock#11 --> &sbi->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sbi->lock);
                               lock(mapping.invalidate_lock#11);
                               lock(&sbi->lock);
  lock(&mm->mmap_lock);

 *** DEADLOCK ***

1 lock held by syz-executor.2/20096:
 #0: ffff88802a6e3090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x77/0xd0 fs/reiserfs/lock.c:27

stack backtrace:
CPU: 0 PID: 20096 Comm: syz-executor.2 Not tainted 6.2.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
 check_noncircular+0x2cc/0x390 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+0x1898/0x6ae0 kernel/locking/lockdep.c:3831
 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
 lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
 __might_fault+0xb2/0x110 mm/memory.c:5647
 reiserfs_ioctl+0x11c/0x340 fs/reiserfs/ioctl.c:96
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fdd3aa8c0c9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fdd3b6fc168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fdd3abac050 RCX: 00007fdd3aa8c0c9
RDX: 0000000020000140 RSI: 0000000080087601 RDI: 0000000000000003
RBP: 00007fdd3aae7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffef62a46df R14: 00007fdd3b6fc300 R15: 0000000000022000
 </TASK>

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-upstream-fs 2023/01/22 14:58 upstream 2241ab53cbb5 cc0f9968 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in reiserfs_get_block
ci2-upstream-fs 2022/12/19 16:07 upstream f9ff5644bcc0 05494336 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in reiserfs_get_block
* Struck through repros no longer work on HEAD.