====================================================== WARNING: possible circular locking dependency detected 4.14.291-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/15611 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+0x20/0x330 drivers/tty/serial/8250/8250_port.c:1891 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:1016 splice_direct_to_actor+0x25a/0x700 fs/splice.c:971 do_splice_direct+0x164/0x210 fs/splice.c:1059 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+0x46/0xbb -> #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+0x28d/0x330 drivers/tty/serial/8250/8250_port.c:1915 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1888 [inline] serial8250_default_handle_irq+0x8a/0x1f0 drivers/tty/serial/8250/8250_port.c:1931 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 arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0xa3/0xe0 kernel/locking/spinlock.c:192 spin_unlock_irqrestore include/linux/spinlock.h:372 [inline] __wake_up_common_lock+0xcd/0x140 kernel/sched/wait.c:127 unix_dgram_recvmsg+0x27d/0xc60 net/unix/af_unix.c:2172 ___sys_recvmsg+0x20b/0x4d0 net/socket.c:2221 __sys_recvmmsg+0x1f3/0x5d0 net/socket.c:2329 SYSC_recvmmsg net/socket.c:2405 [inline] SyS_recvmmsg+0x125/0x140 net/socket.c:2394 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb 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 *** 4 locks held by syz-executor.1/15611: #0: (&u->iolock){+.+.}, at: [] unix_dgram_recvmsg+0x1e4/0xc60 net/unix/af_unix.c:2146 #1: (&(&i->lock)->rlock){-.-.}, at: [] spin_lock include/linux/spinlock.h:317 [inline] #1: (&(&i->lock)->rlock){-.-.}, at: [] serial8250_interrupt+0x3a/0x210 drivers/tty/serial/8250/8250_core.c:119 #2: (&port_lock_key){-.-.}, at: [] serial8250_handle_irq.part.0+0x20/0x330 drivers/tty/serial/8250/8250_port.c:1891 #3: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref+0x1b/0x80 drivers/tty/tty_ldisc.c:305 stack backtrace: CPU: 1 PID: 15611 Comm: syz-executor.1 Not tainted 4.14.291-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 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+0x28d/0x330 drivers/tty/serial/8250/8250_port.c:1915 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1888 [inline] serial8250_default_handle_irq+0x8a/0x1f0 drivers/tty/serial/8250/8250_port.c:1931 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:576 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa3/0xe0 kernel/locking/spinlock.c:192 RSP: 0018:ffff88806880f858 EFLAGS: 00000286 ORIG_RAX: ffffffffffffffc8 RAX: 1ffffffff11e1341 RBX: 0000000000000286 RCX: 1ffff1100d3f916d RDX: dffffc0000000000 RSI: ffff888069fc8b48 RDI: 0000000000000286 RBP: ffff8880b44d5e00 R08: ffff8880ba434d30 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000304 R15: 1ffff1100d101f10 spin_unlock_irqrestore include/linux/spinlock.h:372 [inline] __wake_up_common_lock+0xcd/0x140 kernel/sched/wait.c:127 unix_dgram_recvmsg+0x27d/0xc60 net/unix/af_unix.c:2172 ___sys_recvmsg+0x20b/0x4d0 net/socket.c:2221 __sys_recvmmsg+0x1f3/0x5d0 net/socket.c:2329 SYSC_recvmmsg net/socket.c:2405 [inline] SyS_recvmmsg+0x125/0x140 net/socket.c:2394 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7ff441201279 RSP: 002b:00007ff43fb55168 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007ff441314050 RCX: 00007ff441201279 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007ff44125b2e9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdc83cb2df R14: 00007ff43fb55300 R15: 0000000000022000 audit: type=1800 audit(1662219107.725:6): pid=15612 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.1" name="file0" dev="sda1" ino=13876 res=0 audit: type=1800 audit(1662219109.525:7): pid=15729 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="file0" dev="loop5" ino=288 res=0 audit: type=1804 audit(1662219109.535:8): pid=15729 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir3057010797/syzkaller.j8jJAT/199/file0/file0" dev="loop5" ino=288 res=1 libceph: connect [d::]:6789 error -101 libceph: mon0 [d::]:6789 connect error libceph: connect [d::]:6789 error -101 libceph: mon0 [d::]:6789 connect error ceph: No mds server is up or the cluster is laggy audit: type=1800 audit(1662219110.745:9): pid=15773 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.3" name="file0" dev="sda1" ino=14225 res=0 audit: type=1804 audit(1662219110.755:10): pid=15773 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.3" name="/root/syzkaller-testdir3632815020/syzkaller.fH3oNv/236/file0" dev="sda1" ino=14225 res=1 audit: type=1800 audit(1662219110.855:11): pid=15775 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="file0" dev="sda1" ino=14573 res=0 libceph: connect [d::]:6789 error -101 audit: type=1804 audit(1662219110.875:12): pid=15775 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir3057010797/syzkaller.j8jJAT/200/file0" dev="sda1" ino=14573 res=1 audit: type=1800 audit(1662219111.605:13): pid=15795 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="file0" dev="sda1" ino=14597 res=0 audit: type=1804 audit(1662219111.605:14): pid=15795 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir863169496/syzkaller.c8JVDh/190/file0" dev="sda1" ino=14597 res=1 audit: type=1800 audit(1662219111.605:15): pid=15796 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.0" name="file0" dev="sda1" ino=14598 res=0 libceph: mon0 [d::]:6789 connect error ceph: No mds server is up or the cluster is laggy libceph: connect [d::]:6789 error -101 libceph: mon0 [d::]:6789 connect error kauditd_printk_skb: 7 callbacks suppressed audit: type=1800 audit(1662219114.096:23): pid=15834 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.0" name="file0" dev="sda1" ino=14610 res=0 libceph: connect [d::]:6789 error -101 libceph: mon0 [d::]:6789 connect error ceph: No mds server is up or the cluster is laggy audit: type=1804 audit(1662219114.096:24): pid=15834 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir1022169906/syzkaller.TUWnSQ/200/file0" dev="sda1" ino=14610 res=1 audit: type=1800 audit(1662219114.596:25): pid=15835 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.3" name="file0" dev="sda1" ino=14611 res=0 audit: type=1804 audit(1662219114.606:26): pid=15835 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.3" name="/root/syzkaller-testdir3632815020/syzkaller.fH3oNv/238/file0" dev="sda1" ino=14611 res=1 audit: type=1800 audit(1662219114.636:27): pid=15833 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="file0" dev="sda1" ino=14612 res=0 audit: type=1804 audit(1662219114.646:28): pid=15833 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir863169496/syzkaller.c8JVDh/191/file0" dev="sda1" ino=14612 res=1 audit: type=1800 audit(1662219114.906:29): pid=15837 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.4" name="file0" dev="sda1" ino=14613 res=0 audit: type=1804 audit(1662219114.916:30): pid=15837 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir1991377646/syzkaller.xA6K8d/223/file0" dev="sda1" ino=14613 res=1 audit: type=1800 audit(1662219115.346:31): pid=15850 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.3" name="file0" dev="sda1" ino=13892 res=0 audit: type=1804 audit(1662219115.376:32): pid=15850 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.3" name="/root/syzkaller-testdir3632815020/syzkaller.fH3oNv/239/file0" dev="sda1" ino=13892 res=1