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.0.219/4834 is trying to acquire lock: ffff888026e6d090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 but task is already holding lock: ffff888078b6a558 (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:1891 [inline] sb_start_pagefault include/linux/fs.h:1995 [inline] filemap_page_mkwrite+0x167/0x630 mm/filemap.c:3545 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009 do_shared_fault mm/memory.c:4694 [inline] do_fault mm/memory.c:4762 [inline] handle_pte_fault mm/memory.c:5029 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x1b10/0x3e60 mm/memory.c:5292 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340 handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487 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/0x330 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:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747 reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 reiserfs_dirty_inode+0xf0/0x240 fs/reiserfs/super.c:704 __mark_inode_dirty+0x2eb/0xe90 fs/fs-writeback.c:2443 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+0x2d3/0x340 fs/inode.c:2178 filemap_page_mkwrite+0x271/0x630 mm/filemap.c:3546 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009 do_shared_fault mm/memory.c:4694 [inline] do_fault mm/memory.c:4762 [inline] handle_pte_fault mm/memory.c:5029 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x1b10/0x3e60 mm/memory.c:5292 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340 handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487 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.0.219/4834: #0: ffff888027e99058 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff888027e99058 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline] #0: ffff888027e99058 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5382 #1: ffff888078b6a558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009 stack backtrace: CPU: 1 PID: 4834 Comm: syz.0.219 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747 reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 reiserfs_dirty_inode+0xf0/0x240 fs/reiserfs/super.c:704 __mark_inode_dirty+0x2eb/0xe90 fs/fs-writeback.c:2443 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+0x2d3/0x340 fs/inode.c:2178 filemap_page_mkwrite+0x271/0x630 mm/filemap.c:3546 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009 do_shared_fault mm/memory.c:4694 [inline] do_fault mm/memory.c:4762 [inline] handle_pte_fault mm/memory.c:5029 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x1b10/0x3e60 mm/memory.c:5292 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340 handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f9f0775736b Code: fa 10 73 2d 83 fa 08 73 46 83 fa 04 73 16 83 fa 01 7c 10 8a 0e 74 0a 0f b7 74 16 fe 66 89 74 17 fe 88 0f c3 8b 4c 16 fc 8b 36 <89> 4c 17 fc 89 37 c3 c5 fa 6f 06 c5 fa 6f 4c 16 f0 c5 fa 7f 07 c5 RSP: 002b:00007ffc06249b58 EFLAGS: 00010202 RAX: 0000200000000400 RBX: 0000000000000004 RCX: 0000000000737562 RDX: 0000000000000006 RSI: 0000000075622f2e RDI: 0000200000000400 RBP: 0000000000000000 R08: 0000001b2e120000 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000009 R12: 00007f9f079e5fac R13: 00007f9f079e5fa0 R14: fffffffffffffffe R15: 0000000000000006