====================================================== WARNING: possible circular locking dependency detected 4.14.298-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/10732 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: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+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 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.1/10732: #0: (&(ptlock_ptr(page))->rlock#2){+.+.}, at: [] spin_lock include/linux/spinlock.h:317 [inline] #0: (&(ptlock_ptr(page))->rlock#2){+.+.}, at: [] zap_pte_range mm/memory.c:1336 [inline] #0: (&(ptlock_ptr(page))->rlock#2){+.+.}, at: [] zap_pmd_range mm/memory.c:1479 [inline] #0: (&(ptlock_ptr(page))->rlock#2){+.+.}, at: [] zap_pud_range mm/memory.c:1508 [inline] #0: (&(ptlock_ptr(page))->rlock#2){+.+.}, at: [] zap_p4d_range mm/memory.c:1529 [inline] #0: (&(ptlock_ptr(page))->rlock#2){+.+.}, at: [] unmap_page_range+0x889/0x1d90 mm/memory.c:1550 #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: 10732 Comm: syz-executor.1 Not tainted 4.14.298-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 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:578 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 20 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 20 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 20 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 20 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 20 bytes leftover after parsing attributes in process `syz-executor.3'. EXT4-fs (loop2): mounted filesystem without journal. Opts: ,errors=continue tmpfs: Bad value 'interleave=static :' for mount option 'mpol' device team0 entered promiscuous mode device team_slave_0 entered promiscuous mode tmpfs: Bad value 'interleave=static :' for mount option 'mpol' EXT4-fs (loop2): mounted filesystem without journal. Opts: ,errors=continue device team_slave_1 entered promiscuous mode batman_adv: batadv0: Adding interface: team0 tmpfs: Bad value 'interleave=static :' for mount option 'mpol' tmpfs: Bad value 'interleave=static :' for mount option 'mpol' batman_adv: batadv0: The MTU of interface team0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. tmpfs: Bad value 'interleave=static :' for mount option 'mpol' batman_adv: batadv0: Interface activated: team0 batman_adv: batadv0: Interface deactivated: team0 batman_adv: batadv0: Removing interface: team0 bridge0: port 3(team0) entered blocking state bridge0: port 3(team0) entered disabled state bridge0: port 3(team0) entered blocking state bridge0: port 3(team0) entered forwarding state EXT4-fs (loop2): mounted filesystem without journal. Opts: ,errors=continue bridge0: port 3(team0) entered disabled state batman_adv: batadv0: Adding interface: team0 batman_adv: batadv0: The MTU of interface team0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Interface activated: team0 batman_adv: batadv0: Interface deactivated: team0 batman_adv: batadv0: Removing interface: team0 bridge0: port 3(team0) entered blocking state bridge0: port 3(team0) entered disabled state bridge0: port 3(team0) entered blocking state bridge0: port 3(team0) entered forwarding state tmpfs: Bad value 'interleave=static :' for mount option 'mpol' bridge0: port 3(team0) entered disabled state tmpfs: Bad value 'interleave=static :' for mount option 'mpol' EXT4-fs (loop2): mounted filesystem without journal. Opts: ,errors=continue batman_adv: batadv0: Adding interface: team0