REISERFS (device loop0): checking transaction log (loop0)
REISERFS (device loop0): Using tea hash to sort names
REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage.
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/4436 is trying to acquire lock:
ffff888077869090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27

but task is already holding lock:
ffff888073fa2558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (sb_pagefaults#2){.+.+}-{0:0}:
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1897 [inline]
       sb_start_pagefault include/linux/fs.h:2001 [inline]
       filemap_page_mkwrite+0x167/0x630 mm/filemap.c:3545
       do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009
       wp_page_shared+0x167/0x370 mm/memory.c:3358
       handle_pte_fault mm/memory.c:5047 [inline]
       __handle_mm_fault mm/memory.c:5171 [inline]
       handle_mm_fault+0x1b1b/0x3d40 mm/memory.c:5292
       do_user_addr_fault+0x58e/0xb20 arch/x86/mm/fault.c:1338
       handle_page_fault arch/x86/mm/fault.c:1429 [inline]
       exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482
       asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608

-> #1 (&mm->mmap_lock){++++}-{3:3}:
       __might_fault+0xc2/0x120 mm/memory.c:5850
       reiserfs_ioctl+0x13b/0x320 fs/reiserfs/ioctl.c:96
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&sbi->lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3095 [inline]
       check_prevs_add kernel/locking/lockdep.c:3214 [inline]
       validate_chain kernel/locking/lockdep.c:3830 [inline]
       __lock_acquire+0x2d18/0x7c40 kernel/locking/lockdep.c:5063
       lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5678
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747
       reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27
       reiserfs_dirty_inode+0x10d/0x260 fs/reiserfs/super.c:704
       __mark_inode_dirty+0x2e7/0xe80 fs/fs-writeback.c:2500
       generic_update_time fs/inode.c:1946 [inline]
       inode_update_time fs/inode.c:1959 [inline]
       __file_update_time+0x21d/0x240 fs/inode.c:2147
       file_update_time+0x2f3/0x370 fs/inode.c:2178
       filemap_page_mkwrite+0x271/0x630 mm/filemap.c:3546
       do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009
       wp_page_shared+0x167/0x370 mm/memory.c:3358
       handle_pte_fault mm/memory.c:5047 [inline]
       __handle_mm_fault mm/memory.c:5171 [inline]
       handle_mm_fault+0x1b1b/0x3d40 mm/memory.c:5292
       do_user_addr_fault+0x58e/0xb20 arch/x86/mm/fault.c:1338
       handle_page_fault arch/x86/mm/fault.c:1429 [inline]
       exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482
       asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608

other info that might help us debug this:

Chain exists of:
  &sbi->lock --> &mm->mmap_lock --> sb_pagefaults#2

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sb_pagefaults#2);
                               lock(&mm->mmap_lock);
                               lock(sb_pagefaults#2);
  lock(&sbi->lock);

 *** DEADLOCK ***

2 locks held by syz.0.17/4436:
 #0: ffff88807b35b5d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88807b35b5d8 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline]
 #0: ffff88807b35b5d8 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5382
 #1: ffff888073fa2558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009

stack backtrace:
CPU: 0 PID: 4436 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3095 [inline]
 check_prevs_add kernel/locking/lockdep.c:3214 [inline]
 validate_chain kernel/locking/lockdep.c:3830 [inline]
 __lock_acquire+0x2d18/0x7c40 kernel/locking/lockdep.c:5063
 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5678
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747
 reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27
 reiserfs_dirty_inode+0x10d/0x260 fs/reiserfs/super.c:704
 __mark_inode_dirty+0x2e7/0xe80 fs/fs-writeback.c:2500
 generic_update_time fs/inode.c:1946 [inline]
 inode_update_time fs/inode.c:1959 [inline]
 __file_update_time+0x21d/0x240 fs/inode.c:2147
 file_update_time+0x2f3/0x370 fs/inode.c:2178
 filemap_page_mkwrite+0x271/0x630 mm/filemap.c:3546
 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009
 wp_page_shared+0x167/0x370 mm/memory.c:3358
 handle_pte_fault mm/memory.c:5047 [inline]
 __handle_mm_fault mm/memory.c:5171 [inline]
 handle_mm_fault+0x1b1b/0x3d40 mm/memory.c:5292
 do_user_addr_fault+0x58e/0xb20 arch/x86/mm/fault.c:1338
 handle_page_fault arch/x86/mm/fault.c:1429 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f7ab716d02d
Code: 4c 17 f0 c3 66 0f 1f 84 00 00 00 00 00 48 8b 4c 16 f8 48 8b 36 48 89 37 48 89 4c 17 f8 c3 c5 fe 6f 54 16 e0 c5 fe 6f 5c 16 c0 <c5> fe 7f 07 c5 fe 7f 4f 20 c5 fe 7f 54 17 e0 c5 fe 7f 5c 17 c0 e9
RSP: 002b:00007ffd1978ebc8 EFLAGS: 00010283
RAX: 00002000000001c0 RBX: 0000000000000004 RCX: 0000000000000007
RDX: 0000000000000055 RSI: 0000001b2d021239 RDI: 00002000000001c0
RBP: fffffffffffffffe R08: 0000001b2d420000 R09: 0000000000000001
R10: 0000000000000055 R11: 0000000000000001 R12: 0000000000000000
R13: 00007f7ab7425fac R14: 0000000000017d85 R15: 00007f7ab7425fa0
 </TASK>