====================================================== WARNING: possible circular locking dependency detected 6.1.0-rc6-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/8256 is trying to acquire lock: ffff888097a0a650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_dirty_inode+0xf4/0x250 fs/btrfs/inode.c:6085 but task is already holding lock: ffff888097a0a558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x19b/0x680 mm/memory.c:2978 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (sb_pagefaults#2){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1826 [inline] sb_start_pagefault include/linux/fs.h:1930 [inline] btrfs_page_mkwrite+0x1b5/0x1140 fs/btrfs/inode.c:8415 do_page_mkwrite+0x19b/0x680 mm/memory.c:2978 do_shared_fault mm/memory.c:4619 [inline] do_fault mm/memory.c:4687 [inline] handle_pte_fault mm/memory.c:4955 [inline] __handle_mm_fault+0x2280/0x3a40 mm/memory.c:5097 handle_mm_fault+0x1cc/0x780 mm/memory.c:5218 do_user_addr_fault+0x475/0x1210 arch/x86/mm/fault.c:1428 handle_page_fault arch/x86/mm/fault.c:1519 [inline] exc_page_fault+0x98/0x170 arch/x86/mm/fault.c:1575 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 -> #4 (&mm->mmap_lock#2){++++}-{3:3}: __might_fault mm/memory.c:5646 [inline] __might_fault+0x10c/0x180 mm/memory.c:5639 _copy_to_user+0x29/0x150 lib/usercopy.c:29 copy_to_user include/linux/uaccess.h:169 [inline] btrfs_ioctl_get_subvol_rootref+0x74e/0xad0 fs/btrfs/ioctl.c:3203 btrfs_ioctl+0x2de6/0x5be0 fs/btrfs/ioctl.c:5556 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x197/0x210 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #3 (btrfs-root-00){++++}-{3:3}: down_read_nested+0x9e/0x450 kernel/locking/rwsem.c:1634 __btrfs_tree_read_lock+0x32/0x350 fs/btrfs/locking.c:134 btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline] btrfs_read_lock_root_node+0x82/0x3a0 fs/btrfs/locking.c:279 btrfs_search_slot_get_root fs/btrfs/ctree.c:1665 [inline] btrfs_search_slot+0x3ca/0x2c70 fs/btrfs/ctree.c:1985 btrfs_update_root+0xdb/0x630 fs/btrfs/root-tree.c:132 _btrfs_ioctl_set_received_subvol+0x730/0xc50 fs/btrfs/ioctl.c:4867 btrfs_ioctl_set_received_subvol_32 fs/btrfs/ioctl.c:4917 [inline] btrfs_ioctl+0x1db6/0x5be0 fs/btrfs/ioctl.c:5521 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x197/0x210 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #2 (btrfs_trans_num_extwriters){++++}-{0:0}: join_transaction+0x1b3/0x10f0 fs/btrfs/transaction.c:299 start_transaction+0x407/0x1470 fs/btrfs/transaction.c:658 btrfs_truncate fs/btrfs/inode.c:8604 [inline] btrfs_setsize fs/btrfs/inode.c:5213 [inline] btrfs_setattr+0x5ec/0x1420 fs/btrfs/inode.c:5248 notify_change+0xcd4/0x1440 fs/attr.c:420 do_truncate+0x140/0x200 fs/open.c:65 handle_truncate fs/namei.c:3216 [inline] do_open fs/namei.c:3561 [inline] path_openat+0x2143/0x2860 fs/namei.c:3713 do_filp_open+0x1ba/0x410 fs/namei.c:3740 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x143/0x1f0 fs/open.c:1337 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #1 (btrfs_trans_num_writers){++++}-{0:0}: join_transaction+0x18e/0x10f0 fs/btrfs/transaction.c:298 start_transaction+0x407/0x1470 fs/btrfs/transaction.c:658 btrfs_truncate fs/btrfs/inode.c:8604 [inline] btrfs_setsize fs/btrfs/inode.c:5213 [inline] btrfs_setattr+0x5ec/0x1420 fs/btrfs/inode.c:5248 notify_change+0xcd4/0x1440 fs/attr.c:420 do_truncate+0x140/0x200 fs/open.c:65 handle_truncate fs/namei.c:3216 [inline] do_open fs/namei.c:3561 [inline] path_openat+0x2143/0x2860 fs/namei.c:3713 do_filp_open+0x1ba/0x410 fs/namei.c:3740 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x143/0x1f0 fs/open.c:1337 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (sb_internal#2){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1826 [inline] sb_start_intwrite include/linux/fs.h:1948 [inline] start_transaction+0x878/0x1470 fs/btrfs/transaction.c:652 btrfs_dirty_inode+0xf4/0x250 fs/btrfs/inode.c:6085 btrfs_update_time+0x25a/0x2c0 fs/btrfs/inode.c:6127 inode_update_time fs/inode.c:1871 [inline] __file_update_time fs/inode.c:2088 [inline] file_update_time+0x1fb/0x270 fs/inode.c:2119 btrfs_page_mkwrite+0x4f1/0x1140 fs/btrfs/inode.c:8431 do_page_mkwrite+0x19b/0x680 mm/memory.c:2978 do_shared_fault mm/memory.c:4619 [inline] do_fault mm/memory.c:4687 [inline] handle_pte_fault mm/memory.c:4955 [inline] __handle_mm_fault+0x2280/0x3a40 mm/memory.c:5097 handle_mm_fault+0x1cc/0x780 mm/memory.c:5218 do_user_addr_fault+0x475/0x1210 arch/x86/mm/fault.c:1428 handle_page_fault arch/x86/mm/fault.c:1519 [inline] exc_page_fault+0x98/0x170 arch/x86/mm/fault.c:1575 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 other info that might help us debug this: Chain exists of: sb_internal#2 --> &mm->mmap_lock#2 --> sb_pagefaults#2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_pagefaults#2); lock(&mm->mmap_lock#2); lock(sb_pagefaults#2); lock(sb_internal#2); *** DEADLOCK *** 2 locks held by syz-executor.0/8256: #0: ffff88801c91d858 (&mm->mmap_lock#2){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:117 [inline] #0: ffff88801c91d858 (&mm->mmap_lock#2){++++}-{3:3}, at: do_user_addr_fault+0xa51/0x1210 arch/x86/mm/fault.c:1379 #1: ffff888097a0a558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x19b/0x680 mm/memory.c:2978 stack backtrace: CPU: 1 PID: 8256 Comm: syz-executor.0 Not tainted 6.1.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2177 check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1826 [inline] sb_start_intwrite include/linux/fs.h:1948 [inline] start_transaction+0x878/0x1470 fs/btrfs/transaction.c:652 btrfs_dirty_inode+0xf4/0x250 fs/btrfs/inode.c:6085 btrfs_update_time+0x25a/0x2c0 fs/btrfs/inode.c:6127 inode_update_time fs/inode.c:1871 [inline] __file_update_time fs/inode.c:2088 [inline] file_update_time+0x1fb/0x270 fs/inode.c:2119 btrfs_page_mkwrite+0x4f1/0x1140 fs/btrfs/inode.c:8431 do_page_mkwrite+0x19b/0x680 mm/memory.c:2978 do_shared_fault mm/memory.c:4619 [inline] do_fault mm/memory.c:4687 [inline] handle_pte_fault mm/memory.c:4955 [inline] __handle_mm_fault+0x2280/0x3a40 mm/memory.c:5097 handle_mm_fault+0x1cc/0x780 mm/memory.c:5218 do_user_addr_fault+0x475/0x1210 arch/x86/mm/fault.c:1428 handle_page_fault arch/x86/mm/fault.c:1519 [inline] exc_page_fault+0x98/0x170 arch/x86/mm/fault.c:1575 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0033:0x7fd7e7486ca6 Code: 82 63 01 00 00 48 89 d1 f3 a4 c3 80 fa 08 73 12 80 fa 04 73 1e 80 fa 01 77 26 72 05 0f b6 0e 88 0f c3 48 8b 4c 16 f8 48 8b 36 <48> 89 4c 17 f8 48 89 37 c3 8b 4c 16 fc 8b 36 89 4c 17 fc 89 37 c3 RSP: 002b:00007ffd9d0fefd8 EFLAGS: 00010202 RAX: 00000000200007c0 RBX: 0000000000000000 RCX: 006c6c75662f7665 RDX: 000000000000000a RSI: 6c75662f7665642f RDI: 00000000200007c0 RBP: 00007ffd9d0ff098 R08: 00007fd7e7400000 R09: 00007fd7e7000000 R10: 00007fd7e7005d60 R11: 0000000000000246 R12: 0000000000178b0b R13: 00007ffd9d0ff0c0 R14: 00007fd7e75abf80 R15: 0000000000000032