====================================================== WARNING: possible circular locking dependency detected 6.1.0-rc7-syzkaller-33097-ge3cb714fb489 #0 Not tainted ------------------------------------------------------ syz-executor.4/3499 is trying to acquire lock: ffff0000c47f83f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0xc0/0x330 fs/jbd2/checkpoint.c:110 but task is already holding lock: ffff0000cff7d080 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline] ffff0000cff7d080 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_buffered_write_iter+0x50/0x294 fs/ext4/file.c:279 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sb->s_type->i_mutex_key#8){++++}-{3:3}: down_read+0x5c/0x78 kernel/locking/rwsem.c:1509 inode_lock_shared include/linux/fs.h:766 [inline] ext4_bmap+0x34/0x1c8 fs/ext4/inode.c:3164 bmap+0x40/0x6c fs/inode.c:1798 jbd2_journal_bmap fs/jbd2/journal.c:977 [inline] __jbd2_journal_erase fs/jbd2/journal.c:1789 [inline] jbd2_journal_flush+0x2a8/0x55c fs/jbd2/journal.c:2492 ext4_ioctl_checkpoint fs/ext4/ioctl.c:1081 [inline] __ext4_ioctl fs/ext4/ioctl.c:1586 [inline] ext4_ioctl+0x1cb8/0x2378 fs/ext4/ioctl.c:1606 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x140 arch/arm64/kernel/syscall.c:197 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584 -> #0 (&journal->j_checkpoint_mutex){+.+.}-{3:3}: 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+0x1530/0x3084 kernel/locking/lockdep.c:5055 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5668 __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603 mutex_lock_io_nested+0x6c/0x88 kernel/locking/mutex.c:833 __jbd2_log_wait_for_space+0xc0/0x330 fs/jbd2/checkpoint.c:110 add_transaction_credits+0x4b4/0x604 fs/jbd2/transaction.c:298 start_this_handle+0x2a0/0x7fc fs/jbd2/transaction.c:422 jbd2__journal_start+0x148/0x1f0 fs/jbd2/transaction.c:520 __ext4_journal_start_sb+0x124/0x1dc fs/ext4/ext4_jbd2.c:105 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_dirty_inode+0x40/0x98 fs/ext4/inode.c:6007 __mark_inode_dirty+0x104/0x354 fs/fs-writeback.c:2408 generic_update_time fs/inode.c:1859 [inline] inode_update_time fs/inode.c:1872 [inline] __file_update_time fs/inode.c:2088 [inline] file_modified_flags+0x2dc/0x330 fs/inode.c:2161 file_modified+0x24/0x34 fs/inode.c:2177 ext4_write_checks fs/ext4/file.c:264 [inline] ext4_buffered_write_iter+0x12c/0x294 fs/ext4/file.c:280 ext4_file_write_iter+0x84/0x408 fs/ext4/file.c:700 __kernel_write_iter+0xe0/0x284 fs/read_write.c:517 __kernel_write+0x88/0xb8 fs/read_write.c:537 __dump_emit fs/coredump.c:804 [inline] dump_emit+0x1e4/0x480 fs/coredump.c:874 writenote+0xc8/0x15c fs/binfmt_elf.c:1488 write_note_info fs/binfmt_elf.c:1951 [inline] elf_core_dump+0x1374/0x16dc fs/binfmt_elf.c:2299 do_coredump+0x8b0/0x1010 fs/coredump.c:755 get_signal+0x788/0xb2c kernel/signal.c:2844 do_signal+0xd4/0x438 arch/arm64/kernel/signal.c:1076 do_notify_resume+0xc0/0x1f0 arch/arm64/kernel/signal.c:1129 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_da+0xb8/0x16c arch/arm64/kernel/entry-common.c:516 el0t_64_sync_handler+0xcc/0xf0 arch/arm64/kernel/entry-common.c:658 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#8); lock(&journal->j_checkpoint_mutex); lock(&sb->s_type->i_mutex_key#8); lock(&journal->j_checkpoint_mutex); *** DEADLOCK *** 2 locks held by syz-executor.4/3499: #0: ffff0000c403a460 (sb_writers#3){.+.+}-{0:0}, at: do_coredump+0x8a4/0x1010 fs/coredump.c:754 #1: ffff0000cff7d080 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline] #1: ffff0000cff7d080 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_buffered_write_iter+0x50/0x294 fs/ext4/file.c:279 stack backtrace: CPU: 1 PID: 3499 Comm: syz-executor.4 Not tainted 6.1.0-rc7-syzkaller-33097-ge3cb714fb489 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 print_circular_bug+0x2c4/0x2c8 kernel/locking/lockdep.c:2055 check_noncircular+0x14c/0x154 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+0x1530/0x3084 kernel/locking/lockdep.c:5055 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5668 __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603 mutex_lock_io_nested+0x6c/0x88 kernel/locking/mutex.c:833 __jbd2_log_wait_for_space+0xc0/0x330 fs/jbd2/checkpoint.c:110 add_transaction_credits+0x4b4/0x604 fs/jbd2/transaction.c:298 start_this_handle+0x2a0/0x7fc fs/jbd2/transaction.c:422 jbd2__journal_start+0x148/0x1f0 fs/jbd2/transaction.c:520 __ext4_journal_start_sb+0x124/0x1dc fs/ext4/ext4_jbd2.c:105 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_dirty_inode+0x40/0x98 fs/ext4/inode.c:6007 __mark_inode_dirty+0x104/0x354 fs/fs-writeback.c:2408 generic_update_time fs/inode.c:1859 [inline] inode_update_time fs/inode.c:1872 [inline] __file_update_time fs/inode.c:2088 [inline] file_modified_flags+0x2dc/0x330 fs/inode.c:2161 file_modified+0x24/0x34 fs/inode.c:2177 ext4_write_checks fs/ext4/file.c:264 [inline] ext4_buffered_write_iter+0x12c/0x294 fs/ext4/file.c:280 ext4_file_write_iter+0x84/0x408 fs/ext4/file.c:700 __kernel_write_iter+0xe0/0x284 fs/read_write.c:517 __kernel_write+0x88/0xb8 fs/read_write.c:537 __dump_emit fs/coredump.c:804 [inline] dump_emit+0x1e4/0x480 fs/coredump.c:874 writenote+0xc8/0x15c fs/binfmt_elf.c:1488 write_note_info fs/binfmt_elf.c:1951 [inline] elf_core_dump+0x1374/0x16dc fs/binfmt_elf.c:2299 do_coredump+0x8b0/0x1010 fs/coredump.c:755 get_signal+0x788/0xb2c kernel/signal.c:2844 do_signal+0xd4/0x438 arch/arm64/kernel/signal.c:1076 do_notify_resume+0xc0/0x1f0 arch/arm64/kernel/signal.c:1129 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_da+0xb8/0x16c arch/arm64/kernel/entry-common.c:516 el0t_64_sync_handler+0xcc/0xf0 arch/arm64/kernel/entry-common.c:658 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584