reiserfs: enabling write barrier flush mode REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage. ====================================================== WARNING: possible circular locking dependency detected 5.15.189-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/4600 is trying to acquire lock: ffff8880727c4090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 but task is already holding lock: ffff88802165e558 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (sb_pagefaults){.+.+}-{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+0x120/0x660 mm/filemap.c:3367 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 do_shared_fault mm/memory.c:4328 [inline] do_fault mm/memory.c:4396 [inline] handle_pte_fault mm/memory.c:4650 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1d4b/0x43c0 mm/memory.c:4883 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1357 handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:205 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline] copyout lib/iov_iter.c:157 [inline] copy_page_to_iter_iovec lib/iov_iter.c:228 [inline] __copy_page_to_iter lib/iov_iter.c:861 [inline] copy_page_to_iter+0x49e/0x910 lib/iov_iter.c:889 filemap_read+0x1d94/0x2480 mm/filemap.c:2698 call_read_iter include/linux/fs.h:2166 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x725/0xcf0 fs/read_write.c:485 ksys_read+0x14d/0x250 fs/read_write.c:623 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #1 (&mm->mmap_lock){++++}-{3:3}: __might_fault+0xb3/0x110 mm/memory.c:5357 reiserfs_ioctl+0x13b/0x330 fs/reiserfs/ioctl.c:96 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #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+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 reiserfs_dirty_inode+0xf0/0x240 fs/reiserfs/super.c:704 __mark_inode_dirty+0x2b0/0xc60 fs/fs-writeback.c:2464 generic_update_time+0x1cd/0x1f0 fs/inode.c:1881 inode_update_time fs/inode.c:1894 [inline] file_update_time+0x38b/0x400 fs/inode.c:2083 filemap_page_mkwrite+0x242/0x660 mm/filemap.c:3368 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 do_shared_fault mm/memory.c:4328 [inline] do_fault mm/memory.c:4396 [inline] handle_pte_fault mm/memory.c:4650 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1d4b/0x43c0 mm/memory.c:4883 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1357 handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:205 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline] copyout lib/iov_iter.c:157 [inline] copy_page_to_iter_iovec lib/iov_iter.c:228 [inline] __copy_page_to_iter lib/iov_iter.c:861 [inline] copy_page_to_iter+0x49e/0x910 lib/iov_iter.c:889 filemap_read+0x1d94/0x2480 mm/filemap.c:2698 call_read_iter include/linux/fs.h:2166 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x725/0xcf0 fs/read_write.c:485 ksys_read+0x14d/0x250 fs/read_write.c:623 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Chain exists of: &sbi->lock --> &mm->mmap_lock --> sb_pagefaults Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_pagefaults); lock(&mm->mmap_lock); lock(sb_pagefaults); lock(&sbi->lock); *** DEADLOCK *** 3 locks held by syz-executor.0/4600: #0: ffff888076d3dc70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1058 #1: ffff888079815528 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #1: ffff888079815528 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1298 #2: ffff88802165e558 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 stack backtrace: CPU: 0 PID: 4600 Comm: syz-executor.0 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 check_noncircular+0x274/0x310 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+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 reiserfs_dirty_inode+0xf0/0x240 fs/reiserfs/super.c:704 __mark_inode_dirty+0x2b0/0xc60 fs/fs-writeback.c:2464 generic_update_time+0x1cd/0x1f0 fs/inode.c:1881 inode_update_time fs/inode.c:1894 [inline] file_update_time+0x38b/0x400 fs/inode.c:2083 filemap_page_mkwrite+0x242/0x660 mm/filemap.c:3368 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 do_shared_fault mm/memory.c:4328 [inline] do_fault mm/memory.c:4396 [inline] handle_pte_fault mm/memory.c:4650 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1d4b/0x43c0 mm/memory.c:4883 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1357 handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0010:copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:206 Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 90 90 90 90 90 90 90 0f 01 cb 83 fa 40 0f 82 70 ff ff ff 89 d1 a4 31 c0 0f 01 ca c3 90 90 90 90 90 90 90 90 90 90 89 d1 83 f8 RSP: 0018:ffffc9000340f920 EFLAGS: 00050206 RAX: ffffffff83d8a301 RBX: 00000000200017ff RCX: 0000000000001000 RDX: 0000000000001000 RSI: ffff888066a6d000 RDI: 0000000020001740 RBP: 0000000000001000 R08: dffffc0000000000 R09: ffffed100cd4dc00 R10: 0000000000000000 R11: 0000000000000200 R12: ffff888066a6d000 R13: 0000000000001000 R14: 00007ffffffff000 R15: 0000000020002740 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline] copyout lib/iov_iter.c:157 [inline] copy_page_to_iter_iovec lib/iov_iter.c:228 [inline] __copy_page_to_iter lib/iov_iter.c:861 [inline] copy_page_to_iter+0x49e/0x910 lib/iov_iter.c:889 filemap_read+0x1d94/0x2480 mm/filemap.c:2698 call_read_iter include/linux/fs.h:2166 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x725/0xcf0 fs/read_write.c:485 ksys_read+0x14d/0x250 fs/read_write.c:623 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f398d0caae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f398c44c0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f398d1e9f80 RCX: 00007f398d0caae9 RDX: 0000000000002020 RSI: 0000000020001740 RDI: 0000000000000005 RBP: 00007f398d11647a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f398d1e9f80 R15: 00007ffc0de11c18 ---------------- Code disassembly (best guess): 0: 89 d1 mov %edx,%ecx 2: c1 e9 03 shr $0x3,%ecx 5: 83 e2 07 and $0x7,%edx 8: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi) b: 89 d1 mov %edx,%ecx d: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) f: 31 c0 xor %eax,%eax 11: 0f 01 ca clac 14: c3 ret 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 0f 01 cb stac 1f: 83 fa 40 cmp $0x40,%edx 22: 0f 82 70 ff ff ff jb 0xffffff98 28: 89 d1 mov %edx,%ecx * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: 31 c0 xor %eax,%eax 2e: 0f 01 ca clac 31: c3 ret 32: 90 nop 33: 90 nop 34: 90 nop 35: 90 nop 36: 90 nop 37: 90 nop 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 89 d1 mov %edx,%ecx 3e: 83 .byte 0x83 3f: f8 clc