====================================================== WARNING: possible circular locking dependency detected 6.1.84-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/4699 is trying to acquire lock: ffff0000d7eaa3f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x1a4/0x5cc fs/jbd2/checkpoint.c:71 but task is already holding lock: ffff0000e732c030 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] ffff0000e732c030 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_buffered_write_iter+0x9c/0x538 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#9){++++}-{3:3}: down_read+0x64/0x308 kernel/locking/rwsem.c:1520 inode_lock_shared include/linux/fs.h:768 [inline] ext4_bmap+0x58/0x35c fs/ext4/inode.c:3176 bmap+0xa8/0xe8 fs/inode.c:1842 jbd2_journal_bmap fs/jbd2/journal.c:977 [inline] __jbd2_journal_erase fs/jbd2/journal.c:1794 [inline] jbd2_journal_flush+0x4bc/0xa5c fs/jbd2/journal.c:2496 ext4_ioctl_checkpoint fs/ext4/ioctl.c:1086 [inline] __ext4_ioctl fs/ext4/ioctl.c:1594 [inline] ext4_ioctl+0x3834/0x6afc fs/ext4/ioctl.c:1614 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+0x14c/0x1c8 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 -> #0 (&journal->j_checkpoint_mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x3338/0x7680 kernel/locking/lockdep.c:5049 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5662 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603 mutex_lock_io_nested+0x6c/0x88 kernel/locking/mutex.c:833 __jbd2_log_wait_for_space+0x1a4/0x5cc fs/jbd2/checkpoint.c:71 add_transaction_credits+0x7dc/0xafc fs/jbd2/transaction.c:298 start_this_handle+0x5c4/0x13ac fs/jbd2/transaction.c:422 jbd2__journal_start+0x298/0x544 fs/jbd2/transaction.c:520 __ext4_journal_start_sb+0x304/0x6f4 fs/ext4/ext4_jbd2.c:105 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_dirty_inode+0x9c/0x100 fs/ext4/inode.c:6069 __mark_inode_dirty+0x2f8/0x1354 fs/fs-writeback.c:2433 mark_inode_dirty include/linux/fs.h:2541 [inline] generic_write_end+0x200/0x3fc fs/buffer.c:2184 ext4_da_write_end+0x540/0x940 fs/ext4/inode.c:3108 generic_perform_write+0x384/0x55c mm/filemap.c:3828 ext4_buffered_write_iter+0x2e0/0x538 fs/ext4/file.c:285 ext4_file_write_iter+0x18c/0x1638 __kernel_write_iter+0x264/0x5f8 fs/read_write.c:517 dump_emit_page fs/coredump.c:881 [inline] dump_user_range+0x384/0x6b8 fs/coredump.c:908 elf_core_dump+0x2fe4/0x3714 fs/binfmt_elf.c:2312 do_coredump+0x14a0/0x2234 fs/coredump.c:755 get_signal+0xfd8/0x158c kernel/signal.c:2848 do_signal arch/arm64/kernel/signal.c:1076 [inline] do_notify_resume+0x3ac/0x3474 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_svc+0x9c/0x168 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#9); lock(&journal->j_checkpoint_mutex); lock(&sb->s_type->i_mutex_key#9); lock(&journal->j_checkpoint_mutex); *** DEADLOCK *** 2 locks held by syz-executor.3/4699: #0: ffff0000d7e9c460 (sb_writers#3){.+.+}-{0:0}, at: do_coredump+0x1478/0x2234 fs/coredump.c:754 #1: ffff0000e732c030 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff0000e732c030 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_buffered_write_iter+0x9c/0x538 fs/ext4/file.c:279 stack backtrace: CPU: 1 PID: 4699 Comm: syz-executor.3 Not tainted 6.1.84-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call trace: dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2048 check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x3338/0x7680 kernel/locking/lockdep.c:5049 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5662 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603 mutex_lock_io_nested+0x6c/0x88 kernel/locking/mutex.c:833 __jbd2_log_wait_for_space+0x1a4/0x5cc fs/jbd2/checkpoint.c:71 add_transaction_credits+0x7dc/0xafc fs/jbd2/transaction.c:298 start_this_handle+0x5c4/0x13ac fs/jbd2/transaction.c:422 jbd2__journal_start+0x298/0x544 fs/jbd2/transaction.c:520 __ext4_journal_start_sb+0x304/0x6f4 fs/ext4/ext4_jbd2.c:105 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_dirty_inode+0x9c/0x100 fs/ext4/inode.c:6069 __mark_inode_dirty+0x2f8/0x1354 fs/fs-writeback.c:2433 mark_inode_dirty include/linux/fs.h:2541 [inline] generic_write_end+0x200/0x3fc fs/buffer.c:2184 ext4_da_write_end+0x540/0x940 fs/ext4/inode.c:3108 generic_perform_write+0x384/0x55c mm/filemap.c:3828 ext4_buffered_write_iter+0x2e0/0x538 fs/ext4/file.c:285 ext4_file_write_iter+0x18c/0x1638 __kernel_write_iter+0x264/0x5f8 fs/read_write.c:517 dump_emit_page fs/coredump.c:881 [inline] dump_user_range+0x384/0x6b8 fs/coredump.c:908 elf_core_dump+0x2fe4/0x3714 fs/binfmt_elf.c:2312 do_coredump+0x14a0/0x2234 fs/coredump.c:755 get_signal+0xfd8/0x158c kernel/signal.c:2848 do_signal arch/arm64/kernel/signal.c:1076 [inline] do_notify_resume+0x3ac/0x3474 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_svc+0x9c/0x168 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585