====================================================== WARNING: possible circular locking dependency detected 5.15.182-syzkaller #0 Not tainted ------------------------------------------------------ syz.4.699/7114 is trying to acquire lock: ffff0000e8183090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27 but task is already holding lock: ffff0000e892a558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x13c/0x358 mm/memory.c:2922 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:1811 [inline] sb_start_pagefault include/linux/fs.h:1910 [inline] filemap_page_mkwrite+0x1a4/0x9c8 mm/filemap.c:3367 do_page_mkwrite+0x13c/0x358 mm/memory.c:2922 wp_page_shared+0x14c/0x398 mm/memory.c:3259 do_wp_page+0x7c0/0x994 mm/memory.c:3360 handle_pte_fault mm/memory.c:4668 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1770/0x2950 mm/memory.c:4883 __do_page_fault arch/arm64/mm/fault.c:505 [inline] do_page_fault+0x694/0xad4 arch/arm64/mm/fault.c:605 do_mem_abort+0x6c/0x1ac arch/arm64/mm/fault.c:819 el0_da+0x90/0x1fc arch/arm64/kernel/entry-common.c:494 el0t_64_sync_handler+0xd8/0xe4 arch/arm64/kernel/entry-common.c:629 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 -> #1 (&mm->mmap_lock){++++}-{3:3}: __might_fault+0xc8/0x128 mm/memory.c:5357 reiserfs_ioctl+0x144/0x4b4 fs/reiserfs/ioctl.c:96 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:860 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 -> #0 (&sbi->lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2928/0x651c kernel/locking/lockdep.c:5012 lock_acquire+0x1f4/0x620 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x194/0x1edc kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0xac/0x11c kernel/locking/mutex.c:743 reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27 reiserfs_dirty_inode+0xe0/0x200 fs/reiserfs/super.c:704 __mark_inode_dirty+0x2b0/0x1070 fs/fs-writeback.c:2464 generic_update_time+0x210/0x238 fs/inode.c:1881 inode_update_time fs/inode.c:1894 [inline] file_update_time+0x318/0x390 fs/inode.c:2083 filemap_page_mkwrite+0x324/0x9c8 mm/filemap.c:3368 do_page_mkwrite+0x13c/0x358 mm/memory.c:2922 wp_page_shared+0x14c/0x398 mm/memory.c:3259 do_wp_page+0x7c0/0x994 mm/memory.c:3360 handle_pte_fault mm/memory.c:4668 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1770/0x2950 mm/memory.c:4883 __do_page_fault arch/arm64/mm/fault.c:505 [inline] do_page_fault+0x694/0xad4 arch/arm64/mm/fault.c:605 do_mem_abort+0x6c/0x1ac arch/arm64/mm/fault.c:819 el0_da+0x90/0x1fc arch/arm64/kernel/entry-common.c:494 el0t_64_sync_handler+0xd8/0xe4 arch/arm64/kernel/entry-common.c:629 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 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.4.699/7114: #0: ffff0000d3891dd8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff0000d3891dd8 (&mm->mmap_lock){++++}-{3:3}, at: do_page_fault+0x364/0xad4 arch/arm64/mm/fault.c:586 #1: ffff0000e892a558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x13c/0x358 mm/memory.c:2922 stack backtrace: CPU: 0 PID: 7114 Comm: syz.4.699 Not tainted 5.15.182-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call trace: dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2011 check_noncircular+0x240/0x2d4 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2928/0x651c kernel/locking/lockdep.c:5012 lock_acquire+0x1f4/0x620 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x194/0x1edc kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0xac/0x11c kernel/locking/mutex.c:743 reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27 reiserfs_dirty_inode+0xe0/0x200 fs/reiserfs/super.c:704 __mark_inode_dirty+0x2b0/0x1070 fs/fs-writeback.c:2464 generic_update_time+0x210/0x238 fs/inode.c:1881 inode_update_time fs/inode.c:1894 [inline] file_update_time+0x318/0x390 fs/inode.c:2083 filemap_page_mkwrite+0x324/0x9c8 mm/filemap.c:3368 do_page_mkwrite+0x13c/0x358 mm/memory.c:2922 wp_page_shared+0x14c/0x398 mm/memory.c:3259 do_wp_page+0x7c0/0x994 mm/memory.c:3360 handle_pte_fault mm/memory.c:4668 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1770/0x2950 mm/memory.c:4883 __do_page_fault arch/arm64/mm/fault.c:505 [inline] do_page_fault+0x694/0xad4 arch/arm64/mm/fault.c:605 do_mem_abort+0x6c/0x1ac arch/arm64/mm/fault.c:819 el0_da+0x90/0x1fc arch/arm64/kernel/entry-common.c:494 el0t_64_sync_handler+0xd8/0xe4 arch/arm64/kernel/entry-common.c:629 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584