====================================================== WARNING: possible circular locking dependency detected 5.15.164-syzkaller #0 Not tainted ------------------------------------------------------ syz.2.836/7280 is trying to acquire lock: ffff888019c42518 (&sighand->siglock){-.-.}-{2:2}, at: __lock_task_sighand+0x11a/0x290 kernel/signal.c:1404 but task is already holding lock: ffff8880b9a35bb8 (lock#11){+.+.}-{2:2}, at: local_lock_acquire+0xd/0x170 include/linux/local_lock_internal.h:28 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (lock#11){+.+.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 local_lock_acquire+0x29/0x170 include/linux/local_lock_internal.h:29 __mmap_lock_do_trace_acquire_returned+0x7c/0x340 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:137 [inline] stack_map_get_build_id_offset+0x612/0x930 kernel/bpf/stackmap.c:185 __bpf_get_stack+0x495/0x570 kernel/bpf/stackmap.c:496 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1490 [inline] bpf_get_stack_raw_tp+0x1b2/0x220 kernel/trace/bpf_trace.c:1480 0xffffffffa002a53e bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1917 trace_tlb_flush+0xed/0x110 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x748/0xa30 context_switch kernel/sched/core.c:5016 [inline] __schedule+0x1167/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 freezable_schedule include/linux/freezer.h:172 [inline] do_nanosleep+0x1bc/0x7b0 kernel/time/hrtimer.c:2045 hrtimer_nanosleep+0x24d/0x490 kernel/time/hrtimer.c:2098 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1313 [inline] __se_sys_clock_nanosleep+0x323/0x3b0 kernel/time/posix-timers.c:1290 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #2 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:368 raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 raw_spin_rq_lock kernel/sched/sched.h:1326 [inline] rq_lock kernel/sched/sched.h:1621 [inline] task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11495 sched_cgroup_fork+0x2d3/0x330 kernel/sched/core.c:4466 copy_process+0x224a/0x3ef0 kernel/fork.c:2320 kernel_clone+0x210/0x960 kernel/fork.c:2604 kernel_thread+0x168/0x1e0 kernel/fork.c:2656 rest_init+0x21/0x330 init/main.c:706 start_kernel+0x48c/0x540 init/main.c:1140 secondary_startup_64_no_verify+0xb1/0xbb -> #1 (&p->pi_lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xae/0x1300 kernel/sched/core.c:4030 signal_wake_up_state kernel/signal.c:770 [inline] signal_wake_up include/linux/sched/signal.h:421 [inline] complete_signal+0x5a0/0x9a0 kernel/signal.c:1062 __send_signal+0xaaf/0xd40 kernel/signal.c:1182 do_notify_parent+0xc1e/0xf00 kernel/signal.c:2113 exit_notify kernel/exit.c:731 [inline] do_exit+0x1464/0x2480 kernel/exit.c:894 do_group_exit+0x144/0x310 kernel/exit.c:996 __do_sys_exit_group kernel/exit.c:1007 [inline] __se_sys_exit_group kernel/exit.c:1005 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1005 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&sighand->siglock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x11a/0x290 kernel/signal.c:1404 lock_task_sighand include/linux/sched/signal.h:704 [inline] do_send_sig_info kernel/signal.c:1293 [inline] group_send_sig_info+0x23f/0x2d0 kernel/signal.c:1442 bpf_send_signal_common+0x2d8/0x420 kernel/trace/bpf_trace.c:824 ____bpf_send_signal kernel/trace/bpf_trace.c:829 [inline] bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:827 bpf_prog_9fbc3d1d47c9b36c+0x1a/0xd64 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run4+0x1ea/0x390 kernel/trace/bpf_trace.c:1919 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:44 [inline] __mmap_lock_do_trace_acquire_returned+0x2d6/0x340 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:137 [inline] do_user_addr_fault arch/x86/mm/fault.c:1298 [inline] handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x564/0x700 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568 other info that might help us debug this: Chain exists of: &sighand->siglock --> &rq->__lock --> lock#11 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#11); lock(&rq->__lock); lock(lock#11); lock(&sighand->siglock); *** DEADLOCK *** 5 locks held by syz.2.836/7280: #0: ffff88801bf78f28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88801bf78f28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault arch/x86/mm/fault.c:1298 [inline] #0: ffff88801bf78f28 (&mm->mmap_lock){++++}-{3:3}, at: handle_page_fault arch/x86/mm/fault.c:1445 [inline] #0: ffff88801bf78f28 (&mm->mmap_lock){++++}-{3:3}, at: exc_page_fault+0x181/0x700 arch/x86/mm/fault.c:1501 #1: ffff8880b9a35bb8 (lock#11){+.+.}-{2:2}, at: local_lock_acquire+0xd/0x170 include/linux/local_lock_internal.h:28 #2: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 #3: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 #4: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 stack backtrace: CPU: 0 PID: 7280 Comm: syz.2.836 Not tainted 5.15.164-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x11a/0x290 kernel/signal.c:1404 lock_task_sighand include/linux/sched/signal.h:704 [inline] do_send_sig_info kernel/signal.c:1293 [inline] group_send_sig_info+0x23f/0x2d0 kernel/signal.c:1442 bpf_send_signal_common+0x2d8/0x420 kernel/trace/bpf_trace.c:824 ____bpf_send_signal kernel/trace/bpf_trace.c:829 [inline] bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:827 bpf_prog_9fbc3d1d47c9b36c+0x1a/0xd64 bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run4+0x1ea/0x390 kernel/trace/bpf_trace.c:1919 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:44 [inline] __mmap_lock_do_trace_acquire_returned+0x2d6/0x340 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_read_trylock include/linux/mmap_lock.h:137 [inline] do_user_addr_fault arch/x86/mm/fault.c:1298 [inline] handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x564/0x700 arch/x86/mm/fault.c:1501 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568 RIP: 0033:0x7f21305fc7c6 Code: ff 48 83 e8 01 48 89 d6 bf 01 00 00 00 48 c1 e0 0e 48 c1 ee 06 48 01 c8 48 89 d1 81 e6 ff 3f 00 00 48 c1 e9 03 83 e1 07 d3 e7 <40> 84 bc 06 20 20 00 00 0f 85 27 fd ff ff e9 ce fd ff ff e8 12 5e RSP: 002b:00007ffed8cab1a0 EFLAGS: 00010202 RAX: 000000110c298000 RBX: 00007f21313db720 RCX: 0000000000000007 RDX: ffffffff81ea45be RSI: 0000000000002916 RDI: 0000000000000080 RBP: 0000000000000000 R08: 00007f2130896000 R09: 00007f2130898000 R10: 0000000081ea45c2 R11: 0000000000000001 R12: ffffffff81ea4e66 R13: 00007f21308ac018 R14: 0000000000000008 R15: 0000000000000240