====================================================== WARNING: possible circular locking dependency detected 6.1.82-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/17015 is trying to acquire lock: ffff88807e4403f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x213/0x760 fs/jbd2/checkpoint.c:71 but task is already holding lock: ffff8880802c2c20 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] ffff8880802c2c20 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_buffered_write_iter+0xaf/0x3a0 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}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 down_read+0xad/0xa30 kernel/locking/rwsem.c:1520 inode_lock_shared include/linux/fs.h:768 [inline] ext4_bmap+0x4b/0x410 fs/ext4/inode.c:3176 bmap+0xa1/0xd0 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+0x5b5/0xc40 fs/jbd2/journal.c:2496 ext4_ioctl_checkpoint fs/ext4/ioctl.c:1086 [inline] __ext4_ioctl fs/ext4/ioctl.c:1594 [inline] ext4_ioctl+0x3986/0x5f60 fs/ext4/ioctl.c:1614 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #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+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] mutex_lock_io_nested+0x134/0xab0 kernel/locking/mutex.c:833 __jbd2_log_wait_for_space+0x213/0x760 fs/jbd2/checkpoint.c:71 add_transaction_credits fs/jbd2/transaction.c:298 [inline] start_this_handle+0x1040/0x21b0 fs/jbd2/transaction.c:422 jbd2__journal_start+0x2d1/0x5c0 fs/jbd2/transaction.c:520 __ext4_journal_start_sb+0x19b/0x410 fs/ext4/ext4_jbd2.c:105 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_dirty_inode+0x8b/0x100 fs/ext4/inode.c:6069 __mark_inode_dirty+0x331/0xf80 fs/fs-writeback.c:2433 mark_inode_dirty include/linux/fs.h:2541 [inline] generic_write_end+0x180/0x1d0 fs/buffer.c:2184 ext4_da_write_end+0x749/0xa70 fs/ext4/inode.c:3108 generic_perform_write+0x3e9/0x5e0 mm/filemap.c:3828 ext4_buffered_write_iter+0x122/0x3a0 fs/ext4/file.c:285 ext4_file_write_iter+0x1d2/0x1880 __kernel_write_iter+0x2ff/0x710 fs/read_write.c:517 dump_emit_page fs/coredump.c:881 [inline] dump_user_range+0x43d/0x8e0 fs/coredump.c:908 elf_core_dump+0x3d2b/0x4590 fs/binfmt_elf.c:2312 do_coredump+0x18b7/0x2700 fs/coredump.c:755 get_signal+0x1454/0x17d0 kernel/signal.c:2848 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:310 exc_page_fault+0x1c0/0x660 arch/x86/mm/fault.c:1530 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570 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.3/17015: #0: ffff88807e43c460 (sb_writers#4){.+.+}-{0:0}, at: do_coredump+0x1892/0x2700 fs/coredump.c:754 #1: ffff8880802c2c20 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff8880802c2c20 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_buffered_write_iter+0xaf/0x3a0 fs/ext4/file.c:279 stack backtrace: CPU: 0 PID: 17015 Comm: syz-executor.3 Not tainted 6.1.82-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 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+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] mutex_lock_io_nested+0x134/0xab0 kernel/locking/mutex.c:833 __jbd2_log_wait_for_space+0x213/0x760 fs/jbd2/checkpoint.c:71 add_transaction_credits fs/jbd2/transaction.c:298 [inline] start_this_handle+0x1040/0x21b0 fs/jbd2/transaction.c:422 jbd2__journal_start+0x2d1/0x5c0 fs/jbd2/transaction.c:520 __ext4_journal_start_sb+0x19b/0x410 fs/ext4/ext4_jbd2.c:105 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_dirty_inode+0x8b/0x100 fs/ext4/inode.c:6069 __mark_inode_dirty+0x331/0xf80 fs/fs-writeback.c:2433 mark_inode_dirty include/linux/fs.h:2541 [inline] generic_write_end+0x180/0x1d0 fs/buffer.c:2184 ext4_da_write_end+0x749/0xa70 fs/ext4/inode.c:3108 generic_perform_write+0x3e9/0x5e0 mm/filemap.c:3828 ext4_buffered_write_iter+0x122/0x3a0 fs/ext4/file.c:285 ext4_file_write_iter+0x1d2/0x1880 __kernel_write_iter+0x2ff/0x710 fs/read_write.c:517 dump_emit_page fs/coredump.c:881 [inline] dump_user_range+0x43d/0x8e0 fs/coredump.c:908 elf_core_dump+0x3d2b/0x4590 fs/binfmt_elf.c:2312 do_coredump+0x18b7/0x2700 fs/coredump.c:755 get_signal+0x1454/0x17d0 kernel/signal.c:2848 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:310 exc_page_fault+0x1c0/0x660 arch/x86/mm/fault.c:1530 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0033:0x7f623627ddb1 Code: 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 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:0000000000001f00 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f62363ac050 RCX: 00007f623627dda9 RDX: 0000000000000000 RSI: 0000000000001f00 RDI: 00000000c0920400 RBP: 00007f62362ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 000000000000006e R14: 00007f62363ac050 R15: 00007fff8b826488