SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
  cache: sigqueue, object size: 80, buffer size: 112, default order: 0, min order: 0
  node 0: slabs: 18229, objs: 656244, free: 0
======================================================
WARNING: possible circular locking dependency detected
5.10.56 #1 Not tainted
------------------------------------------------------
syz-executor.0/14715 is trying to acquire lock:
ffffffff84d0a8a0 (console_owner){-.-.}-{0:0}, at: console_unlock+0x2e1/0xb30 kernel/printk/printk.c:2498

but task is already holding lock:
ffff88805ca165d8 (&sighand->siglock){-...}-{2:2}, at: force_sig_info_to_task+0x6c/0x3a0 kernel/signal.c:1317

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&sighand->siglock){-...}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x36/0x50 kernel/locking/spinlock.c:159
       __lock_task_sighand+0xd3/0x2f0 kernel/signal.c:1391
       lock_task_sighand include/linux/sched/signal.h:693 [inline]
       task_work_add+0x1db/0x2b0 kernel/task_work.c:58
       io_req_task_work_add fs/io_uring.c:2049 [inline]
       __io_async_wake+0x40b/0x8d0 fs/io_uring.c:4955
       __wake_up_common+0x14c/0x4c0 kernel/sched/wait.c:93
       __wake_up_common_lock+0xd0/0x130 kernel/sched/wait.c:123
       tty_ldisc_lock+0x40/0xb0 drivers/tty/tty_ldisc.c:335
       tty_ldisc_hangup+0x204/0x690 drivers/tty/tty_ldisc.c:744
       __tty_hangup.part.0+0x50d/0x9b0 drivers/tty/tty_io.c:624
       __tty_hangup drivers/tty/tty_io.c:574 [inline]
       tty_vhangup drivers/tty/tty_io.c:697 [inline]
       tty_ioctl+0x103e/0x17c0 drivers/tty/tty_io.c:2683
       vfs_ioctl fs/ioctl.c:48 [inline]
       __do_sys_ioctl fs/ioctl.c:753 [inline]
       __se_sys_ioctl fs/ioctl.c:739 [inline]
       __x64_sys_ioctl+0x196/0x210 fs/ioctl.c:739
       do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

-> #3 (&tty->read_wait){....}-{2:2}:
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x27/0x40 kernel/locking/spinlock.c:151
       spin_lock include/linux/spinlock.h:354 [inline]
       io_poll_double_wake+0x1f8/0x550 fs/io_uring.c:5068
       __wake_up_common+0x14c/0x4c0 kernel/sched/wait.c:93
       __wake_up_common_lock+0xd0/0x130 kernel/sched/wait.c:123
       tty_ldisc_lock+0x55/0xb0 drivers/tty/tty_ldisc.c:336
       tty_ldisc_hangup+0x204/0x690 drivers/tty/tty_ldisc.c:744
       __tty_hangup.part.0+0x50d/0x9b0 drivers/tty/tty_io.c:624
       __tty_hangup drivers/tty/tty_io.c:574 [inline]
       tty_vhangup drivers/tty/tty_io.c:697 [inline]
       tty_ioctl+0x103e/0x17c0 drivers/tty/tty_io.c:2683
       vfs_ioctl fs/ioctl.c:48 [inline]
       __do_sys_ioctl fs/ioctl.c:753 [inline]
       __se_sys_ioctl fs/ioctl.c:739 [inline]
       __x64_sys_ioctl+0x196/0x210 fs/ioctl.c:739
       do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

-> #2 (&tty->write_wait){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x36/0x50 kernel/locking/spinlock.c:159
       __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:122
       tty_port_default_wakeup+0x26/0x40 drivers/tty/tty_port.c:50
       serial8250_tx_chars+0x516/0xb40 drivers/tty/serial/8250/8250_port.c:1844
       serial8250_handle_irq.part.0+0x3f1/0x4c0 drivers/tty/serial/8250/8250_port.c:1931
       serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1904 [inline]
       serial8250_default_handle_irq+0xb8/0x230 drivers/tty/serial/8250/8250_port.c:1947
       serial8250_interrupt+0xf4/0x1a0 drivers/tty/serial/8250/8250_core.c:126
       __handle_irq_event_percpu+0x2ef/0x820 kernel/irq/handle.c:156
       handle_irq_event_percpu kernel/irq/handle.c:196 [inline]
       handle_irq_event+0x102/0x290 kernel/irq/handle.c:213
       handle_edge_irq+0x249/0xd00 kernel/irq/chip.c:819
       asm_call_irq_on_stack+0x12/0x20
       __run_irq_on_irqstack arch/x86/include/asm/irq_stack.h:48 [inline]
       run_irq_on_irqstack_cond arch/x86/include/asm/irq_stack.h:101 [inline]
       handle_irq arch/x86/kernel/irq.c:230 [inline]
       __common_interrupt arch/x86/kernel/irq.c:249 [inline]
       common_interrupt+0xdd/0x190 arch/x86/kernel/irq.c:239
       asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:626
       native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline]
       arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline]
       default_idle+0xe/0x10 arch/x86/kernel/process.c:688
       default_idle_call+0x87/0xd0 kernel/sched/idle.c:112
       cpuidle_idle_call kernel/sched/idle.c:194 [inline]
       do_idle+0x3a9/0x520 kernel/sched/idle.c:300
       cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:396
       secondary_startup_64_no_verify+0xc2/0xcb

-> #1 (&port_lock_key){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x36/0x50 kernel/locking/spinlock.c:159
       serial8250_console_write+0x8dd/0xb20 drivers/tty/serial/8250/8250_port.c:3317
       call_console_drivers kernel/printk/printk.c:1909 [inline]
       console_unlock+0x826/0xb30 kernel/printk/printk.c:2523
       register_console kernel/printk/printk.c:2864 [inline]
       register_console+0x53d/0x800 kernel/printk/printk.c:2754
       univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:690
       console_init+0x361/0x4fa kernel/printk/printk.c:2974
       start_kernel+0x2f2/0x49b init/main.c:984
       secondary_startup_64_no_verify+0xc2/0xcb

-> #0 (console_owner){-.-.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:2985 [inline]
       check_prevs_add kernel/locking/lockdep.c:3110 [inline]
       validate_chain kernel/locking/lockdep.c:3725 [inline]
       __lock_acquire+0x29f6/0x5b20 kernel/locking/lockdep.c:4950
       lock_acquire kernel/locking/lockdep.c:5560 [inline]
       lock_acquire+0x197/0x490 kernel/locking/lockdep.c:5525
       console_lock_spinning_enable kernel/printk/printk.c:1761 [inline]
       console_unlock+0x360/0xb30 kernel/printk/printk.c:2520
       vprintk_emit+0x1da/0x4d0 kernel/printk/printk.c:2052
       vprintk_func+0x8b/0x140 kernel/printk/printk_safe.c:401
       printk+0xba/0xed kernel/printk/printk.c:2100
       warn_alloc.cold+0x82/0x18d mm/page_alloc.c:3979
       __alloc_pages_slowpath.constprop.0+0x1cbf/0x2210 mm/page_alloc.c:4866
       __alloc_pages_nodemask+0x54f/0x680 mm/page_alloc.c:4970
       alloc_pages_current+0x187/0x280 mm/mempolicy.c:2271
       alloc_pages include/linux/gfp.h:547 [inline]
       alloc_slab_page mm/slub.c:1613 [inline]
       allocate_slab+0x297/0x380 mm/slub.c:1764
       new_slab mm/slub.c:1817 [inline]
       new_slab_objects mm/slub.c:2576 [inline]
       ___slab_alloc+0x46c/0x700 mm/slub.c:2739
       __slab_alloc mm/slub.c:2779 [inline]
       slab_alloc_node mm/slub.c:2854 [inline]
       slab_alloc mm/slub.c:2897 [inline]
       kmem_cache_alloc+0x30e/0x350 mm/slub.c:2902
       __sigqueue_alloc+0x1ee/0x560 kernel/signal.c:435
       __send_signal+0x5db/0x1040 kernel/signal.c:1116
       force_sig_info_to_task+0x2a0/0x3a0 kernel/signal.c:1334
       force_sig_fault_to_task kernel/signal.c:1673 [inline]
       force_sig_fault+0xb0/0xf0 kernel/signal.c:1680
       __bad_area_nosemaphore+0x270/0x320 arch/x86/mm/fault.c:832
       __bad_area arch/x86/mm/fault.c:863 [inline]
       bad_area_access_error+0x29c/0x3b0 arch/x86/mm/fault.c:923
       do_user_addr_fault+0x640/0xc30 arch/x86/mm/fault.c:1362
       handle_page_fault arch/x86/mm/fault.c:1436 [inline]
       exc_page_fault+0xa2/0x1a0 arch/x86/mm/fault.c:1492
       asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:571

other info that might help us debug this:

Chain exists of:
  console_owner --> &tty->read_wait --> &sighand->siglock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sighand->siglock);
                               lock(&tty->read_wait);
                               lock(&sighand->siglock);
  lock(console_owner);

 *** DEADLOCK ***

2 locks held by syz-executor.0/14715:
 #0: ffff88805ca165d8 (&sighand->siglock){-...}-{2:2}, at: force_sig_info_to_task+0x6c/0x3a0 kernel/signal.c:1317
 #1: ffffffff84deac20 (console_lock){+.+.}-{0:0}, at: vprintk_func+0x8b/0x140 kernel/printk/printk_safe.c:401

stack backtrace:
CPU: 1 PID: 14715 Comm: syz-executor.0 Not tainted 5.10.56 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:118
 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2120
 check_prev_add kernel/locking/lockdep.c:2985 [inline]
 check_prevs_add kernel/locking/lockdep.c:3110 [inline]
 validate_chain kernel/locking/lockdep.c:3725 [inline]
 __lock_acquire+0x29f6/0x5b20 kernel/locking/lockdep.c:4950
 lock_acquire kernel/locking/lockdep.c:5560 [inline]
 lock_acquire+0x197/0x490 kernel/locking/lockdep.c:5525
 console_lock_spinning_enable kernel/printk/printk.c:1761 [inline]
 console_unlock+0x360/0xb30 kernel/printk/printk.c:2520
 vprintk_emit+0x1da/0x4d0 kernel/printk/printk.c:2052
 vprintk_func+0x8b/0x140 kernel/printk/printk_safe.c:401
 printk+0xba/0xed kernel/printk/printk.c:2100
 warn_alloc.cold+0x82/0x18d mm/page_alloc.c:3979
 __alloc_pages_slowpath.constprop.0+0x1cbf/0x2210 mm/page_alloc.c:4866
 __alloc_pages_nodemask+0x54f/0x680 mm/page_alloc.c:4970
 alloc_pages_current+0x187/0x280 mm/mempolicy.c:2271
 alloc_pages include/linux/gfp.h:547 [inline]
 alloc_slab_page mm/slub.c:1613 [inline]
 allocate_slab+0x297/0x380 mm/slub.c:1764
 new_slab mm/slub.c:1817 [inline]
 new_slab_objects mm/slub.c:2576 [inline]
 ___slab_alloc+0x46c/0x700 mm/slub.c:2739
 __slab_alloc mm/slub.c:2779 [inline]
 slab_alloc_node mm/slub.c:2854 [inline]
 slab_alloc mm/slub.c:2897 [inline]
 kmem_cache_alloc+0x30e/0x350 mm/slub.c:2902
 __sigqueue_alloc+0x1ee/0x560 kernel/signal.c:435
 __send_signal+0x5db/0x1040 kernel/signal.c:1116
 force_sig_info_to_task+0x2a0/0x3a0 kernel/signal.c:1334
 force_sig_fault_to_task kernel/signal.c:1673 [inline]
 force_sig_fault+0xb0/0xf0 kernel/signal.c:1680
 __bad_area_nosemaphore+0x270/0x320 arch/x86/mm/fault.c:832
 __bad_area arch/x86/mm/fault.c:863 [inline]
 bad_area_access_error+0x29c/0x3b0 arch/x86/mm/fault.c:923
 do_user_addr_fault+0x640/0xc30 arch/x86/mm/fault.c:1362
 handle_page_fault arch/x86/mm/fault.c:1436 [inline]
 exc_page_fault+0xa2/0x1a0 arch/x86/mm/fault.c:1492
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:571
RIP: 0033:0x7ffdbbb668cf
Code: 00 00 00 18 6a b6 bb fd 7f 00 00 00 10 00 00 00 00 00 00 f2 1b 00 00 00 00 00 00 01 80 ad fb 00 00 00 00 f0 6b b6 bb fd 7f 00 <01> 38 c0 56 00 00 00 00 00 92 6e 40 00 00 00 00 00 c0 80 56 00 00
RSP: 002b:00007f44b77e5220 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 00007ffdbbb668cf RCX: 00000000004c8d06
RDX: 000000000026bf95 RSI: 000000000000022a RDI: 00000000004d09da
RBP: 000000000040417d R08: ffffffffffffffff R09: 000000000000000e
R10: 00000000004b5bc2 R11: 0000000000000246 R12: 000000000056bf8c
R13: 00007ffdbbb668cf R14: 00007f44b77e5300 R15: 0000000000022000