====================================================== WARNING: possible circular locking dependency detected 5.15.189-syzkaller #0 Not tainted ------------------------------------------------------ syz.5.1138/11244 is trying to acquire lock: ffff888061b96090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 but task is already holding lock: ffff88801f80c558 (sb_pagefaults#5){.+.+}-{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#5){.+.+}-{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 wp_page_shared+0x16b/0x6d0 mm/memory.c:3259 handle_pte_fault mm/memory.c:4668 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1eca/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 __put_user_nocheck_4+0x3/0x11 move_addr_to_user+0x177/0x1e0 net/socket.c:294 ____sys_recvmsg+0x2f3/0x580 net/socket.c:2662 ___sys_recvmsg+0x1af/0x4f0 net/socket.c:2697 do_recvmmsg+0x344/0x7a0 net/socket.c:2791 __sys_recvmmsg net/socket.c:2870 [inline] __do_sys_recvmmsg net/socket.c:2893 [inline] __se_sys_recvmmsg net/socket.c:2886 [inline] __x64_sys_recvmmsg+0x18d/0x240 net/socket.c:2886 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 wp_page_shared+0x16b/0x6d0 mm/memory.c:3259 handle_pte_fault mm/memory.c:4668 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1eca/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 __put_user_nocheck_4+0x3/0x11 move_addr_to_user+0x177/0x1e0 net/socket.c:294 ____sys_recvmsg+0x2f3/0x580 net/socket.c:2662 ___sys_recvmsg+0x1af/0x4f0 net/socket.c:2697 do_recvmmsg+0x344/0x7a0 net/socket.c:2791 __sys_recvmmsg net/socket.c:2870 [inline] __do_sys_recvmmsg net/socket.c:2893 [inline] __se_sys_recvmmsg net/socket.c:2886 [inline] __x64_sys_recvmmsg+0x18d/0x240 net/socket.c:2886 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#5 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_pagefaults#5); lock(&mm->mmap_lock); lock(sb_pagefaults#5); lock(&sbi->lock); *** DEADLOCK *** 2 locks held by syz.5.1138/11244: #0: ffff88802b7f6328 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88802b7f6328 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1298 #1: ffff88801f80c558 (sb_pagefaults#5){.+.+}-{0:0}, at: do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 stack backtrace: CPU: 0 PID: 11244 Comm: syz.5.1138 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 wp_page_shared+0x16b/0x6d0 mm/memory.c:3259 handle_pte_fault mm/memory.c:4668 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1eca/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:__put_user_nocheck_4+0x3/0x11 Code: 00 00 48 39 d9 73 54 0f 01 cb 66 89 01 31 c9 0f 01 ca c3 90 90 90 90 90 48 bb fd ef ff ff ff 7f 00 00 48 39 d9 73 34 0f 01 cb <89> 01 31 c9 0f 01 ca c3 90 90 90 90 90 90 48 bb f9 ef ff ff ff 7f RSP: 0018:ffffc90003e0f8c0 EFLAGS: 00050246 RAX: 0000000000000000 RBX: 00002000003d6008 RCX: 00002000003d6008 RDX: ffffc900121bf000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1ad2dd6 R10: fffffbfff1ad2dd6 R11: 1ffffffff1ad2dd5 R12: 0000000000000000 R13: 0000000000000000 R14: 000000000a202123 R15: ffffc90003e0f9a0 move_addr_to_user+0x177/0x1e0 net/socket.c:294 ____sys_recvmsg+0x2f3/0x580 net/socket.c:2662 ___sys_recvmsg+0x1af/0x4f0 net/socket.c:2697 do_recvmmsg+0x344/0x7a0 net/socket.c:2791 __sys_recvmmsg net/socket.c:2870 [inline] __do_sys_recvmmsg net/socket.c:2893 [inline] __se_sys_recvmmsg net/socket.c:2886 [inline] __x64_sys_recvmmsg+0x18d/0x240 net/socket.c:2886 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: 0033:0x7fae259c99a9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fae23810038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fae25bf1080 RCX: 00007fae259c99a9 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000005 RBP: 00007fae25a4bd69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fae25bf1080 R15: 00007ffdc36aa0e8 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 48 39 d9 cmp %rbx,%rcx 5: 73 54 jae 0x5b 7: 0f 01 cb stac a: 66 89 01 mov %ax,(%rcx) d: 31 c9 xor %ecx,%ecx f: 0f 01 ca clac 12: c3 ret 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 48 bb fd ef ff ff ff movabs $0x7fffffffeffd,%rbx 1f: 7f 00 00 22: 48 39 d9 cmp %rbx,%rcx 25: 73 34 jae 0x5b 27: 0f 01 cb stac * 2a: 89 01 mov %eax,(%rcx) <-- trapping instruction 2c: 31 c9 xor %ecx,%ecx 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: 48 rex.W 39: bb f9 ef ff ff mov $0xffffeff9,%ebx 3e: ff (bad) 3f: 7f .byte 0x7f