====================================================== WARNING: possible circular locking dependency detected 6.2.0-syzkaller-13563-gf915322fe014 #0 Not tainted ------------------------------------------------------ syz-executor.0/17371 is trying to acquire lock: ffff88802bfb03f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x217/0x760 fs/jbd2/checkpoint.c:110 but task is already holding lock: ffff88804ab28e08 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] ffff88804ab28e08 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: ext4_buffered_write_iter+0xaf/0x3a0 fs/ext4/file.c:283 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sb->s_type->i_mutex_key#7){++++}-{3:3}: lock_acquire+0x23e/0x630 kernel/locking/lockdep.c:5669 down_read+0x3d/0x50 kernel/locking/rwsem.c:1520 inode_lock_shared include/linux/fs.h:768 [inline] ext4_bmap+0x4f/0x410 fs/ext4/inode.c:3242 bmap+0xa5/0xe0 fs/inode.c:1799 jbd2_journal_bmap fs/jbd2/journal.c:976 [inline] __jbd2_journal_erase fs/jbd2/journal.c:1788 [inline] jbd2_journal_flush+0x5b9/0xc40 fs/jbd2/journal.c:2491 ext4_ioctl_checkpoint fs/ext4/ioctl.c:1079 [inline] __ext4_ioctl fs/ext4/ioctl.c:1587 [inline] ext4_ioctl+0x3abc/0x6260 fs/ext4/ioctl.c:1607 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:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (&journal->j_checkpoint_mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain+0x166b/0x58e0 kernel/locking/lockdep.c:3832 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056 lock_acquire+0x23e/0x630 kernel/locking/lockdep.c:5669 __mutex_lock_common+0x1d8/0x2530 kernel/locking/mutex.c:603 mutex_lock_io_nested+0x47/0x60 kernel/locking/mutex.c:833 __jbd2_log_wait_for_space+0x217/0x760 fs/jbd2/checkpoint.c:110 add_transaction_credits+0x968/0xc10 fs/jbd2/transaction.c:298 start_this_handle+0x74b/0x1640 fs/jbd2/transaction.c:422 jbd2__journal_start+0x2d5/0x5d0 fs/jbd2/transaction.c:520 __ext4_journal_start_sb+0x3a1/0x8c0 fs/ext4/ext4_jbd2.c:111 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_dirty_inode+0x92/0x110 fs/ext4/inode.c:6105 __mark_inode_dirty+0x413/0x12a0 fs/fs-writeback.c:2421 generic_update_time fs/inode.c:1860 [inline] inode_update_time fs/inode.c:1873 [inline] __file_update_time+0x221/0x240 fs/inode.c:2058 file_modified_flags+0x3e5/0x480 fs/inode.c:2131 ext4_write_checks+0x24a/0x2c0 fs/ext4/file.c:268 ext4_buffered_write_iter+0xbd/0x3a0 fs/ext4/file.c:284 ext4_file_write_iter+0x1d6/0x1930 do_iter_write+0x6ea/0xc50 fs/read_write.c:861 iter_file_splice_write+0x843/0xfe0 fs/splice.c:778 do_splice_from fs/splice.c:856 [inline] direct_splice_actor+0xe7/0x1c0 fs/splice.c:1023 splice_direct_to_actor+0x4c4/0xbd0 fs/splice.c:978 do_splice_direct+0x283/0x3d0 fs/splice.c:1066 do_sendfile+0x620/0xff0 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1317 [inline] __se_sys_sendfile64+0x100/0x1e0 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#7); lock(&journal->j_checkpoint_mutex); lock(&sb->s_type->i_mutex_key#7); lock(&journal->j_checkpoint_mutex); *** DEADLOCK *** 2 locks held by syz-executor.0/17371: #0: ffff88802bf8c460 (sb_writers#4){.+.+}-{0:0}, at: do_sendfile+0x5fb/0xff0 fs/read_write.c:1254 #1: ffff88804ab28e08 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff88804ab28e08 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: ext4_buffered_write_iter+0xaf/0x3a0 fs/ext4/file.c:283 stack backtrace: CPU: 0 PID: 17371 Comm: syz-executor.0 Not tainted 6.2.0-syzkaller-13563-gf915322fe014 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 check_noncircular+0x2fe/0x3b0 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3098 [inline] check_prevs_add kernel/locking/lockdep.c:3217 [inline] validate_chain+0x166b/0x58e0 kernel/locking/lockdep.c:3832 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056 lock_acquire+0x23e/0x630 kernel/locking/lockdep.c:5669 __mutex_lock_common+0x1d8/0x2530 kernel/locking/mutex.c:603 mutex_lock_io_nested+0x47/0x60 kernel/locking/mutex.c:833 __jbd2_log_wait_for_space+0x217/0x760 fs/jbd2/checkpoint.c:110 add_transaction_credits+0x968/0xc10 fs/jbd2/transaction.c:298 start_this_handle+0x74b/0x1640 fs/jbd2/transaction.c:422 jbd2__journal_start+0x2d5/0x5d0 fs/jbd2/transaction.c:520 __ext4_journal_start_sb+0x3a1/0x8c0 fs/ext4/ext4_jbd2.c:111 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_dirty_inode+0x92/0x110 fs/ext4/inode.c:6105 __mark_inode_dirty+0x413/0x12a0 fs/fs-writeback.c:2421 generic_update_time fs/inode.c:1860 [inline] inode_update_time fs/inode.c:1873 [inline] __file_update_time+0x221/0x240 fs/inode.c:2058 file_modified_flags+0x3e5/0x480 fs/inode.c:2131 ext4_write_checks+0x24a/0x2c0 fs/ext4/file.c:268 ext4_buffered_write_iter+0xbd/0x3a0 fs/ext4/file.c:284 ext4_file_write_iter+0x1d6/0x1930 do_iter_write+0x6ea/0xc50 fs/read_write.c:861 iter_file_splice_write+0x843/0xfe0 fs/splice.c:778 do_splice_from fs/splice.c:856 [inline] direct_splice_actor+0xe7/0x1c0 fs/splice.c:1023 splice_direct_to_actor+0x4c4/0xbd0 fs/splice.c:978 do_splice_direct+0x283/0x3d0 fs/splice.c:1066 do_sendfile+0x620/0xff0 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1317 [inline] __se_sys_sendfile64+0x100/0x1e0 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f685f08c0f9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f685fd2b168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f685f1abf80 RCX: 00007f685f08c0f9 RDX: 0000000020000240 RSI: 0000000000000004 RDI: 0000000000000004 RBP: 00007f685f0e7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000007ffc R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff7ad0d0ef R14: 00007f685fd2b300 R15: 0000000000022000