audit: type=1804 audit(1675434888.174:29): pid=13441 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.5" name="/root/syzkaller-testdir506425103/syzkaller.RzBVT3/131/file0" dev="sda1" ino=14401 res=1 ====================================================== WARNING: possible circular locking dependency detected 4.14.304-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/13540 is trying to acquire lock: (&(&gsm->tx_lock)->rlock){-...}, at: [] gsmld_write_wakeup+0x4e/0xd0 drivers/tty/n_gsm.c:2490 but task is already holding lock: (&port_lock_key){-.-.}, at: [] serial8250_handle_irq.part.0+0x20/0x390 drivers/tty/serial/8250/8250_port.c:1894 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&port_lock_key){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:160 uart_write_room+0xd5/0x340 drivers/tty/serial/serial_core.c:643 tty_write_room+0x61/0x80 drivers/tty/tty_ioctl.c:78 gsmld_write+0x69/0x120 drivers/tty/n_gsm.c:2546 do_tty_write drivers/tty/tty_io.c:959 [inline] tty_write+0x410/0x740 drivers/tty/tty_io.c:1043 __vfs_write+0xe4/0x630 fs/read_write.c:480 __kernel_write+0xf5/0x330 fs/read_write.c:501 write_pipe_buf+0x143/0x1c0 fs/splice.c:797 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x326/0x7a0 fs/splice.c:626 splice_from_pipe fs/splice.c:661 [inline] default_file_splice_write+0xc5/0x150 fs/splice.c:809 do_splice_from fs/splice.c:851 [inline] direct_splice_actor+0x115/0x160 fs/splice.c:1018 splice_direct_to_actor+0x27c/0x730 fs/splice.c:973 do_splice_direct+0x164/0x210 fs/splice.c:1061 do_sendfile+0x47f/0xb30 fs/read_write.c:1441 SYSC_sendfile64 fs/read_write.c:1502 [inline] SyS_sendfile64+0xff/0x110 fs/read_write.c:1488 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x5e/0xd3 -> #0 (&(&gsm->tx_lock)->rlock){-...}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:160 gsmld_write_wakeup+0x4e/0xd0 drivers/tty/n_gsm.c:2490 tty_wakeup+0xc3/0xf0 drivers/tty/tty_io.c:533 tty_port_default_wakeup+0x26/0x40 drivers/tty/tty_port.c:49 serial8250_tx_chars+0x3fe/0xc70 drivers/tty/serial/8250/8250_port.c:1828 serial8250_handle_irq.part.0+0x2c7/0x390 drivers/tty/serial/8250/8250_port.c:1918 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1891 [inline] serial8250_default_handle_irq+0x8a/0x1f0 drivers/tty/serial/8250/8250_port.c:1934 serial8250_interrupt+0xf3/0x210 drivers/tty/serial/8250/8250_core.c:129 __handle_irq_event_percpu+0xee/0x7f0 kernel/irq/handle.c:147 handle_irq_event_percpu kernel/irq/handle.c:187 [inline] handle_irq_event+0xed/0x240 kernel/irq/handle.c:204 handle_edge_irq+0x224/0xc40 kernel/irq/chip.c:770 generic_handle_irq_desc include/linux/irqdesc.h:159 [inline] handle_irq+0x35/0x50 arch/x86/kernel/irq_64.c:87 do_IRQ+0x93/0x1d0 arch/x86/kernel/irq.c:230 ret_from_intr+0x0/0x1e other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&port_lock_key); lock(&(&gsm->tx_lock)->rlock); lock(&port_lock_key); lock(&(&gsm->tx_lock)->rlock); *** DEADLOCK *** 3 locks held by syz-executor.0/13540: #0: (&(&i->lock)->rlock){-.-.}, at: [] spin_lock include/linux/spinlock.h:317 [inline] #0: (&(&i->lock)->rlock){-.-.}, at: [] serial8250_interrupt+0x3a/0x210 drivers/tty/serial/8250/8250_core.c:119 #1: (&port_lock_key){-.-.}, at: [] serial8250_handle_irq.part.0+0x20/0x390 drivers/tty/serial/8250/8250_port.c:1894 #2: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref+0x1b/0x80 drivers/tty/tty_ldisc.c:305 stack backtrace: CPU: 1 PID: 13540 Comm: syz-executor.0 Not tainted 4.14.304-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:160 gsmld_write_wakeup+0x4e/0xd0 drivers/tty/n_gsm.c:2490 tty_wakeup+0xc3/0xf0 drivers/tty/tty_io.c:533 tty_port_default_wakeup+0x26/0x40 drivers/tty/tty_port.c:49 serial8250_tx_chars+0x3fe/0xc70 drivers/tty/serial/8250/8250_port.c:1828 serial8250_handle_irq.part.0+0x2c7/0x390 drivers/tty/serial/8250/8250_port.c:1918 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1891 [inline] serial8250_default_handle_irq+0x8a/0x1f0 drivers/tty/serial/8250/8250_port.c:1934 serial8250_interrupt+0xf3/0x210 drivers/tty/serial/8250/8250_core.c:129 __handle_irq_event_percpu+0xee/0x7f0 kernel/irq/handle.c:147 handle_irq_event_percpu kernel/irq/handle.c:187 [inline] handle_irq_event+0xed/0x240 kernel/irq/handle.c:204 handle_edge_irq+0x224/0xc40 kernel/irq/chip.c:770 generic_handle_irq_desc include/linux/irqdesc.h:159 [inline] handle_irq+0x35/0x50 arch/x86/kernel/irq_64.c:87 do_IRQ+0x93/0x1d0 arch/x86/kernel/irq.c:230 common_interrupt+0x93/0x93 arch/x86/entry/entry_64.S:578 RIP: 0033:0x7ffbb77a1386 RSP: 002b:00007ffd9bba49d0 EFLAGS: 00000202 ORIG_RAX: ffffffffffffffc8 RAX: 00007ffbb6f68008 RBX: 00007ffbb79140e8 RCX: 0000001b2fa20000 RDX: 00000000f671bbb9 RSI: 0000001b2fa2be94 RDI: 000000000002817c RBP: 00000000f671bbb9 R08: 0000000000001bb9 R09: 00000000f671bbbd R10: 0000000000000000 R11: 0000000000000000 R12: 00007ffbb7908000 R13: 0000000000000001 R14: 000000000002817c R15: ffffffff831a8c75 audit: type=1804 audit(1675434888.424:30): pid=13441 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.5" name="/root/syzkaller-testdir506425103/syzkaller.RzBVT3/131/file0" dev="sda1" ino=14401 res=1 audit: type=1804 audit(1675434888.434:31): pid=13445 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.2" name="/root/syzkaller-testdir1771304598/syzkaller.dl4a4u/107/file0" dev="sda1" ino=14402 res=1 audit: type=1800 audit(1675434888.804:32): pid=13460 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="file0" dev="sda1" ino=14403 res=0 IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready 8021q: adding VLAN 0 to HW filter on device bond0 IPv6: ADDRCONF(NETDEV_UP): team0: link is not ready 8021q: adding VLAN 0 to HW filter on device team0 chnl_net:chnl_net_open(): err: Unable to register and open device, Err:-19 caif:caif_disconnect_client(): nothing to disconnect audit: type=1804 audit(1675434888.904:33): pid=13460 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir1771304598/syzkaller.dl4a4u/108/file0" dev="sda1" ino=14403 res=1 chnl_net:chnl_flowctrl_cb(): NET flowctrl func called flow: CLOSE/DEINIT chnl_net:chnl_net_open(): state disconnected A link change request failed with some changes committed already. Interface caif0 may have been left with an inconsistent configuration, please check. IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready ====================================================== WARNING: the mand mount option is being deprecated and will be removed in v5.15! ====================================================== 8021q: adding VLAN 0 to HW filter on device bond0 IPv6: ADDRCONF(NETDEV_UP): team0: link is not ready 8021q: adding VLAN 0 to HW filter on device team0 chnl_net:chnl_net_open(): err: Unable to register and open device, Err:-19 caif:caif_disconnect_client(): nothing to disconnect chnl_net:chnl_flowctrl_cb(): NET flowctrl func called flow: CLOSE/DEINIT chnl_net:chnl_net_open(): state disconnected A link change request failed with some changes committed already. Interface caif0 may have been left with an inconsistent configuration, please check. audit: type=1804 audit(1675434889.004:34): pid=13460 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="ToMToU" comm="syz-executor.2" name="/root/syzkaller-testdir1771304598/syzkaller.dl4a4u/108/file0" dev="sda1" ino=14403 res=1 IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready 8021q: adding VLAN 0 to HW filter on device bond0 IPv6: ADDRCONF(NETDEV_UP): team0: link is not ready 8021q: adding VLAN 0 to HW filter on device team0 chnl_net:chnl_net_open(): err: Unable to register and open device, Err:-19 caif:caif_disconnect_client(): nothing to disconnect chnl_net:chnl_flowctrl_cb(): NET flowctrl func called flow: CLOSE/DEINIT chnl_net:chnl_net_open(): state disconnected A link change request failed with some changes committed already. Interface caif0 may have been left with an inconsistent configuration, please check.