netlink: 16 bytes leftover after parsing attributes in process `syz-executor.1'. audit: type=1800 audit(1669769694.598:348): pid=19846 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.3" name="bus" dev="sda1" ino=13923 res=0 ============================================ WARNING: possible recursive locking detected 4.19.211-syzkaller #0 Not tainted -------------------------------------------- syz-executor.1/19858 is trying to acquire lock: 00000000ebd6d46e (&port_lock_key){-.-.}, at: uart_write+0x1ce/0x6f0 drivers/tty/serial/serial_core.c:591 but task is already holding lock: 00000000ebd6d46e (&port_lock_key){-.-.}, at: serial8250_handle_irq.part.0+0x21/0x3d0 drivers/tty/serial/8250/8250_port.c:1876 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&port_lock_key); lock(&port_lock_key); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by syz-executor.1/19858: #0: 00000000b300e355 (sb_writers#3){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline] #0: 00000000b300e355 (sb_writers#3){.+.+}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:360 #1: 000000002c3f1038 (&type->i_mutex_dir_key#3){++++}, at: inode_lock include/linux/fs.h:748 [inline] #1: 000000002c3f1038 (&type->i_mutex_dir_key#3){++++}, at: do_last fs/namei.c:3324 [inline] #1: 000000002c3f1038 (&type->i_mutex_dir_key#3){++++}, at: path_openat+0x1071/0x2df0 fs/namei.c:3537 #2: 00000000fb594bc4 (&(&i->lock)->rlock){-.-.}, at: spin_lock include/linux/spinlock.h:329 [inline] #2: 00000000fb594bc4 (&(&i->lock)->rlock){-.-.}, at: serial8250_interrupt+0x3a/0x240 drivers/tty/serial/8250/8250_core.c:115 #3: 00000000ebd6d46e (&port_lock_key){-.-.}, at: serial8250_handle_irq.part.0+0x21/0x3d0 drivers/tty/serial/8250/8250_port.c:1876 #4: 00000000f9eee23d (&tty->ldisc_sem){++++}, at: tty_ldisc_ref+0x1d/0x80 drivers/tty/tty_ldisc.c:293 stack backtrace: CPU: 1 PID: 19858 Comm: syz-executor.1 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_deadlock_bug kernel/locking/lockdep.c:1764 [inline] check_deadlock kernel/locking/lockdep.c:1808 [inline] validate_chain kernel/locking/lockdep.c:2404 [inline] __lock_acquire.cold+0x121/0x57e kernel/locking/lockdep.c:3416 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:152 uart_write+0x1ce/0x6f0 drivers/tty/serial/serial_core.c:591 n_hdlc_send_frames+0x278/0x470 drivers/tty/n_hdlc.c:403 n_hdlc_tty_wakeup+0xa0/0xc0 drivers/tty/n_hdlc.c:479 tty_wakeup+0xd4/0x110 drivers/tty/tty_io.c:534 tty_port_default_wakeup+0x26/0x40 drivers/tty/tty_port.c:50 serial8250_tx_chars+0x490/0xaf0 drivers/tty/serial/8250/8250_port.c:1813 serial8250_handle_irq.part.0+0x31f/0x3d0 drivers/tty/serial/8250/8250_port.c:1900 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1873 [inline] serial8250_default_handle_irq+0xae/0x220 drivers/tty/serial/8250/8250_port.c:1916 serial8250_interrupt+0x101/0x240 drivers/tty/serial/8250/8250_core.c:125 __handle_irq_event_percpu+0x27e/0x8e0 kernel/irq/handle.c:149 handle_irq_event_percpu kernel/irq/handle.c:189 [inline] handle_irq_event+0x102/0x290 kernel/irq/handle.c:206 handle_edge_irq+0x260/0xcf0 kernel/irq/chip.c:800 generic_handle_irq_desc include/linux/irqdesc.h:155 [inline] handle_irq+0x35/0x50 arch/x86/kernel/irq_64.c:87 do_IRQ+0x93/0x1c0 arch/x86/kernel/irq.c:246 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:670 RIP: 0010:__write_once_size include/linux/compiler.h:290 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x44/0x50 kernel/kcov.c:109 Code: 75 2b 8b 90 60 13 00 00 83 fa 02 75 20 48 8b 88 68 13 00 00 8b 80 64 13 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89 34 d1 <48> 89 11 c3 0f 1f 84 00 00 00 00 00 49 89 f1 49 89 fa 65 48 8b 34 RSP: 0018:ffff888055bb75d8 EFLAGS: 00000216 ORIG_RAX: ffffffffffffffd2 RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc9000700e000 RDX: 0000000000011c4e RSI: ffffffff81b07775 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88804493f888 R13: 0000000000000395 R14: 0000000000001000 R15: ffff88804493f888 touch_buffer fs/buffer.c:59 [inline] __find_get_block+0x2e5/0xde0 fs/buffer.c:1299 sb_find_get_block include/linux/buffer_head.h:346 [inline] recently_deleted fs/ext4/ialloc.c:684 [inline] find_inode_bit+0x213/0x520 fs/ext4/ialloc.c:724 __ext4_new_inode+0x160c/0x5a20 fs/ext4/ialloc.c:916 ext4_create+0x29e/0x5f0 fs/ext4/namei.c:2517 lookup_open+0x893/0x1a20 fs/namei.c:3235 do_last fs/namei.c:3327 [inline] path_openat+0x1094/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_sys_open+0x3b3/0x520 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fe2667090d9 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:00007fe264c7b168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fe266828f80 RCX: 00007fe2667090d9 RDX: 000000000000275a RSI: 00000000200001c0 RDI: ffffffffffffff9c RBP: 00007fe266764ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe2e8b2e9f R14: 00007fe264c7b300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 75 2b jne 0x2d 2: 8b 90 60 13 00 00 mov 0x1360(%rax),%edx 8: 83 fa 02 cmp $0x2,%edx b: 75 20 jne 0x2d d: 48 8b 88 68 13 00 00 mov 0x1368(%rax),%rcx 14: 8b 80 64 13 00 00 mov 0x1364(%rax),%eax 1a: 48 8b 11 mov (%rcx),%rdx 1d: 48 83 c2 01 add $0x1,%rdx 21: 48 39 d0 cmp %rdx,%rax 24: 76 07 jbe 0x2d 26: 48 89 34 d1 mov %rsi,(%rcx,%rdx,8) * 2a: 48 89 11 mov %rdx,(%rcx) <-- trapping instruction 2d: c3 retq 2e: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1) 35: 00 36: 49 89 f1 mov %rsi,%r9 39: 49 89 fa mov %rdi,%r10 3c: 65 gs 3d: 48 rex.W 3e: 8b .byte 0x8b 3f: 34 .byte 0x34