possible deadlock in send

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-4.14	possible deadlock in send_sigio (2)				1	1501d	1501d	0/1	auto-closed as invalid on 2021/02/09 04:22
upstream	possible deadlock in send_sigio fs	C	done		7	1683d	1692d	15/28	fixed on 2020/05/10 10:41
upstream	possible deadlock in send_sigio (2) fs	C	done	done	40	1421d	1534d	19/28	fixed on 2021/03/10 01:48

====================================================== WARNING: possible circular locking dependency detected 4.14.177-syzkaller #0 Not tainted ------------------------------------------------------ rcu_preempt/8 is trying to acquire lock: (tasklist_lock){.?.+}, at: [<ffffffff818f2521>] send_sigio+0xa1/0x1d0 fs/fcntl.c:790 but task is already holding lock: (&(&new->fa_lock)->rlock){-.-.}, at: [<ffffffff818f276e>] kill_fasync_rcu fs/fcntl.c:990 [inline] (&(&new->fa_lock)->rlock){-.-.}, at: [<ffffffff818f276e>] kill_fasync fs/fcntl.c:1011 [inline] (&(&new->fa_lock)->rlock){-.-.}, at: [<ffffffff818f276e>] kill_fasync+0x11e/0x3c0 fs/fcntl.c:1004 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&(&new->fa_lock)->rlock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:160 kill_fasync_rcu fs/fcntl.c:990 [inline] kill_fasync fs/fcntl.c:1011 [inline] kill_fasync+0x11e/0x3c0 fs/fcntl.c:1004 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+0x400/0x9e0 drivers/tty/serial/8250/8250_port.c:1810 serial8250_handle_irq.part.0+0x1f8/0x240 drivers/tty/serial/8250/8250_port.c:1883 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1869 [inline] serial8250_default_handle_irq+0x96/0x110 drivers/tty/serial/8250/8250_port.c:1899 serial8250_interrupt+0xe4/0x1a0 drivers/tty/serial/8250/8250_core.c:129 __handle_irq_event_percpu+0x125/0x7e0 kernel/irq/handle.c:147 handle_irq_event_percpu+0x66/0x120 kernel/irq/handle.c:187 handle_irq_event+0xa2/0x12d kernel/irq/handle.c:204 handle_edge_irq+0x215/0x810 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] del_timer_sync+0x116/0x250 kernel/time/timer.c:1237 schedule_timeout+0x444/0xe40 kernel/time/timer.c:1747 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 -> #3 (&port_lock_key){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:160 serial8250_console_write+0x6c1/0x8e0 drivers/tty/serial/8250/8250_port.c:3236 call_console_drivers kernel/printk/printk.c:1725 [inline] console_unlock+0x9b2/0xec0 kernel/printk/printk.c:2397 vprintk_emit kernel/printk/printk.c:1923 [inline] vprintk_emit+0x1f8/0x600 kernel/printk/printk.c:1888 vprintk_func+0x58/0x152 kernel/printk/printk_safe.c:401 printk+0x9e/0xbc kernel/printk/printk.c:1996 register_console+0x5ec/0x9a0 kernel/printk/printk.c:2716 univ8250_console_init+0x2f/0x3a drivers/tty/serial/8250/8250_core.c:691 console_init+0x46/0x53 kernel/printk/printk.c:2797 start_kernel+0x437/0x676 init/main.c:634 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 -> #2 (console_owner){-.-.}: console_lock_spinning_enable kernel/printk/printk.c:1588 [inline] console_unlock+0x3d4/0xec0 kernel/printk/printk.c:2394 vprintk_emit kernel/printk/printk.c:1923 [inline] vprintk_emit+0x1f8/0x600 kernel/printk/printk.c:1888 vprintk_func+0x58/0x152 kernel/printk/printk_safe.c:401 printk+0x9e/0xbc kernel/printk/printk.c:1996 fail_dump lib/fault-inject.c:44 [inline] should_fail.cold+0xdf/0x14b lib/fault-inject.c:149 should_failslab+0xd6/0x130 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc mm/slab.c:3376 [inline] kmem_cache_alloc+0x44/0x770 mm/slab.c:3550 __sigqueue_alloc+0x1b8/0x3e0 kernel/signal.c:400 __send_signal+0x194/0x1280 kernel/signal.c:1097 specific_send_sig_info kernel/signal.c:1208 [inline] force_sig_info+0x240/0x340 kernel/signal.c:1260 force_sig_info_fault.constprop.0+0x185/0x260 arch/x86/mm/fault.c:225 __bad_area_nosemaphore+0x1d9/0x2a0 arch/x86/mm/fault.c:940 __do_page_fault+0x859/0xb40 arch/x86/mm/fault.c:1412 page_fault+0x45/0x50 arch/x86/entry/entry_64.S:1122 -> #1 (&(&sighand->siglock)->rlock){-.-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:152 spin_lock include/linux/spinlock.h:317 [inline] copy_process.part.0+0x2e5c/0x6a50 kernel/fork.c:1876 copy_process kernel/fork.c:1586 [inline] _do_fork+0x180/0xc80 kernel/fork.c:2070 kernel_thread+0x2f/0x40 kernel/fork.c:2132 create_kthread kernel/kthread.c:255 [inline] kthreadd+0x4f8/0x6f0 kernel/kthread.c:567 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 -> #0 (tasklist_lock){.?.+}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x2d/0x40 kernel/locking/spinlock.c:224 send_sigio+0xa1/0x1d0 fs/fcntl.c:790 kill_fasync_rcu fs/fcntl.c:997 [inline] kill_fasync fs/fcntl.c:1011 [inline] kill_fasync+0x1be/0x3c0 fs/fcntl.c:1004 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+0x400/0x9e0 drivers/tty/serial/8250/8250_port.c:1810 serial8250_handle_irq.part.0+0x1f8/0x240 drivers/tty/serial/8250/8250_port.c:1883 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1869 [inline] serial8250_default_handle_irq+0x96/0x110 drivers/tty/serial/8250/8250_port.c:1899 serial8250_interrupt+0xe4/0x1a0 drivers/tty/serial/8250/8250_core.c:129 __handle_irq_event_percpu+0x125/0x7e0 kernel/irq/handle.c:147 handle_irq_event_percpu+0x66/0x120 kernel/irq/handle.c:187 handle_irq_event+0xa2/0x12d kernel/irq/handle.c:204 handle_edge_irq+0x215/0x810 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] del_timer_sync+0x116/0x250 kernel/time/timer.c:1237 schedule_timeout+0x444/0xe40 kernel/time/timer.c:1747 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 other info that might help us debug this: Chain exists of: tasklist_lock --> &port_lock_key --> &(&new->fa_lock)->rlock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(&new->fa_lock)->rlock); lock(&port_lock_key); lock(&(&new->fa_lock)->rlock); lock(tasklist_lock); *** DEADLOCK *** 6 locks held by rcu_preempt/8: #0: (&(&i->lock)->rlock){-.-.}, at: [<ffffffff8341007b>] spin_lock include/linux/spinlock.h:317 [inline] #0: (&(&i->lock)->rlock){-.-.}, at: [<ffffffff8341007b>] serial8250_interrupt+0x2b/0x1a0 drivers/tty/serial/8250/8250_core.c:119 #1: (&port_lock_key){-.-.}, at: [<ffffffff83420870>] serial8250_handle_irq.part.0+0x20/0x240 drivers/tty/serial/8250/8250_port.c:1872 #2: (&tty->ldisc_sem){++++}, at: [<ffffffff833b058b>] tty_ldisc_ref+0x1b/0x80 drivers/tty/tty_ldisc.c:305 #3: (rcu_read_lock){....}, at: [<ffffffff818f268d>] kill_fasync+0x3d/0x3c0 fs/fcntl.c:1009 #4: (&(&new->fa_lock)->rlock){-.-.}, at: [<ffffffff818f276e>] kill_fasync_rcu fs/fcntl.c:990 [inline] #4: (&(&new->fa_lock)->rlock){-.-.}, at: [<ffffffff818f276e>] kill_fasync fs/fcntl.c:1011 [inline] #4: (&(&new->fa_lock)->rlock){-.-.}, at: [<ffffffff818f276e>] kill_fasync+0x11e/0x3c0 fs/fcntl.c:1004 #5: (&f->f_owner.lock){.?.?}, at: [<ffffffff818f24a4>] send_sigio+0x24/0x1d0 fs/fcntl.c:778 stack backtrace: CPU: 0 PID: 8 Comm: rcu_preempt Not tainted 4.14.177-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x13e/0x194 lib/dump_stack.c:58 print_circular_bug.isra.0.cold+0x1c4/0x282 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+0x2cb3/0x4620 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x2d/0x40 kernel/locking/spinlock.c:224 send_sigio+0xa1/0x1d0 fs/fcntl.c:790 kill_fasync_rcu fs/fcntl.c:997 [inline] kill_fasync fs/fcntl.c:1011 [inline] kill_fasync+0x1be/0x3c0 fs/fcntl.c:1004 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+0x400/0x9e0 drivers/tty/serial/8250/8250_port.c:1810 serial8250_handle_irq.part.0+0x1f8/0x240 drivers/tty/serial/8250/8250_port.c:1883 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1869 [inline] serial8250_default_handle_irq+0x96/0x110 drivers/tty/serial/8250/8250_port.c:1899 serial8250_interrupt+0xe4/0x1a0 drivers/tty/serial/8250/8250_core.c:129 __handle_irq_event_percpu+0x125/0x7e0 kernel/irq/handle.c:147 handle_irq_event_percpu+0x66/0x120 kernel/irq/handle.c:187 handle_irq_event+0xa2/0x12d kernel/irq/handle.c:204 handle_edge_irq+0x215/0x810 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+0x8f/0x8f arch/x86/entry/entry_64.S:576 </IRQ> RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline] RIP: 0010:del_timer_sync+0x116/0x250 kernel/time/timer.c:1237 RSP: 0018:ffff8880a9867c28 EFLAGS: 00000297 ORIG_RAX: ffffffffffffffc8 RAX: ffff8880a9854200 RBX: ffff8880a9867cd0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000297 RBP: 0000000000000297 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a9867d00 R13: ffff8880aea239c0 R14: ffff8880aea239c0 R15: ffff8880a9867cd0 schedule_timeout+0x444/0xe40 kernel/time/timer.c:1747 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 CPU: 1 PID: 16082 Comm: syz-executor.3 Not tainted 4.14.177-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x13e/0x194 lib/dump_stack.c:58 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/0x14b lib/fault-inject.c:149 should_failslab+0xd6/0x130 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc_node mm/slab.c:3297 [inline] kmem_cache_alloc_node_trace+0x292/0x7b0 mm/slab.c:3659 __do_kmalloc_node mm/slab.c:3681 [inline] __kmalloc_node_track_caller+0x38/0x70 mm/slab.c:3696 __kmalloc_reserve.isra.0+0x35/0xd0 net/core/skbuff.c:137 __alloc_skb+0xca/0x4c0 net/core/skbuff.c:205 alloc_skb include/linux/skbuff.h:980 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1159 [inline] netlink_sendmsg+0x7de/0xbe0 net/netlink/af_netlink.c:1853 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xc5/0x100 net/socket.c:656 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062 __sys_sendmsg+0xa3/0x120 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0x27/0x40 net/socket.c:2103 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c829 RSP: 002b:00007f0a158a6c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000004fdcc0 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000009 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000b R13: 0000000000000948 R14: 00000000004d59c0 R15: 00007f0a158a76d4 netlink: 2 bytes leftover after parsing attributes in process `syz-executor.3'. hfs: unable to parse mount options hfs: unable to parse mount options cifs_vfs_err: 27 callbacks suppressed CIFS VFS: Malformed UNC in devname. CIFS VFS: Malformed UNC in devname. CIFS VFS: Malformed UNC in devname. CIFS VFS: Malformed UNC in devname. CIFS VFS: Malformed UNC in devname. CIFS VFS: Malformed UNC in devname. CIFS VFS: Malformed UNC in devname. CIFS VFS: Malformed UNC in devname. overlayfs: fs on '.' does not support file handles, falling back to index=off. CIFS VFS: Malformed UNC in devname. overlayfs: fs on '.' does not support file handles, falling back to index=off. CIFS VFS: Malformed UNC in devname. cifs_vfs_err: 4 callbacks suppressed CIFS VFS: Malformed UNC in devname. CIFS VFS: Malformed UNC in devname. CIFS VFS: Malformed UNC in devname. Unknown ioctl -1068978587 CIFS VFS: Malformed UNC in devname. Unknown ioctl -1068978587 CIFS VFS: Malformed UNC in devname. CIFS VFS: Malformed UNC in devname. CIFS VFS: Malformed UNC in devname. CIFS VFS: Malformed UNC in devname. CIFS VFS: Malformed UNC in devname. CIFS VFS: Malformed UNC in devname.