====================================================== WARNING: possible circular locking dependency detected 6.10.0-rc7-syzkaller-00266-g4d145e3f830b #0 Not tainted ------------------------------------------------------ syz.0.5186/23176 is trying to acquire lock: ffff8880237d0018 (&sighand->siglock){-.-.}-{2:2}, at: __lock_task_sighand+0xc2/0x340 kernel/signal.c:1412 but task is already holding lock: ffff88806b038a80 (lock#14){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff88806b038a80 (lock#14){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x7f/0x790 mm/mmap_lock.c:237 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (lock#14){+.+.}-{2:2}: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_acquire_returned+0x97/0x790 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:164 [inline] stack_map_get_build_id_offset+0x5d9/0x7c0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x6bf/0x700 kernel/bpf/stackmap.c:449 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1994 [inline] bpf_get_stack_raw_tp+0x124/0x160 kernel/trace/bpf_trace.c:1984 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:2011 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2252 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline] bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2444 __bpf_trace_tlb_flush+0xd2/0x110 include/trace/events/tlb.h:38 trace_tlb_flush+0xf3/0x170 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x68b/0xbc0 arch/x86/mm/tlb.c:642 context_switch kernel/sched/core.c:5392 [inline] __schedule+0xd2b/0x5d00 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6837 do_nanosleep+0x216/0x510 kernel/time/hrtimer.c:2030 hrtimer_nanosleep+0x1ab/0x440 kernel/time/hrtimer.c:2083 common_nsleep+0xa1/0xd0 kernel/time/posix-timers.c:1350 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1396 [inline] __se_sys_clock_nanosleep kernel/time/posix-timers.c:1373 [inline] __x64_sys_clock_nanosleep+0x344/0x4a0 kernel/time/posix-timers.c:1373 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&rq->__lock){-.-.}-{2:2}: _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559 raw_spin_rq_lock kernel/sched/sched.h:1406 [inline] _raw_spin_rq_lock_irqsave kernel/sched/sched.h:1425 [inline] rq_lock_irqsave kernel/sched/sched.h:1686 [inline] class_rq_lock_irqsave_constructor kernel/sched/sched.h:1740 [inline] sched_mm_cid_before_execve+0x114/0x5e0 kernel/sched/core.c:12026 exit_signals+0x34d/0x960 kernel/signal.c:3014 do_exit+0x54e/0x2ba0 kernel/exit.c:835 __do_sys_exit kernel/exit.c:992 [inline] __se_sys_exit kernel/exit.c:990 [inline] __x64_sys_exit+0x42/0x50 kernel/exit.c:990 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&sighand->siglock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __lock_task_sighand+0xc2/0x340 kernel/signal.c:1412 lock_task_sighand include/linux/sched/signal.h:746 [inline] do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x290/0x300 kernel/signal.c:1451 bpf_send_signal_common+0x2e8/0x3a0 kernel/trace/bpf_trace.c:881 ____bpf_send_signal_thread kernel/trace/bpf_trace.c:898 [inline] bpf_send_signal_thread+0x16/0x20 kernel/trace/bpf_trace.c:896 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:2011 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2252 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline] bpf_trace_run4+0x245/0x5a0 kernel/trace/bpf_trace.c:2446 __bpf_trace_mmap_lock_acquire_returned+0x134/0x180 include/trace/events/mmap_lock.h:52 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline] __mmap_lock_do_trace_acquire_returned+0x456/0x790 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_write_lock_killable include/linux/mmap_lock.h:123 [inline] __do_sys_munlock mm/mlock.c:697 [inline] __se_sys_munlock mm/mlock.c:688 [inline] __x64_sys_munlock+0x214/0x2c0 mm/mlock.c:688 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &sighand->siglock --> &rq->__lock --> lock#14 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#14); lock(&rq->__lock); lock(lock#14); lock(&sighand->siglock); *** DEADLOCK *** 5 locks held by syz.0.5186/23176: #0: ffff88804613ba98 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:122 [inline] #0: ffff88804613ba98 (&mm->mmap_lock){++++}-{3:3}, at: __do_sys_munlock mm/mlock.c:697 [inline] #0: ffff88804613ba98 (&mm->mmap_lock){++++}-{3:3}, at: __se_sys_munlock mm/mlock.c:688 [inline] #0: ffff88804613ba98 (&mm->mmap_lock){++++}-{3:3}, at: __x64_sys_munlock+0xc8/0x2c0 mm/mlock.c:688 #1: ffff88806b038a80 (lock#14){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #1: ffff88806b038a80 (lock#14){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x7f/0x790 mm/mmap_lock.c:237 #2: ffffffff8dbb1620 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #2: ffffffff8dbb1620 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #2: ffffffff8dbb1620 (rcu_read_lock){....}-{1:2}, at: get_memcg_path_buf mm/mmap_lock.c:139 [inline] #2: ffffffff8dbb1620 (rcu_read_lock){....}-{1:2}, at: get_mm_memcg_path+0xb1/0x6f0 mm/mmap_lock.c:209 #3: ffffffff8dbb1620 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8dbb1620 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8dbb1620 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #3: ffffffff8dbb1620 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x1d6/0x5a0 kernel/trace/bpf_trace.c:2446 #4: ffffffff8dbb1620 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #4: ffffffff8dbb1620 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #4: ffffffff8dbb1620 (rcu_read_lock){....}-{1:2}, at: __lock_task_sighand+0x3f/0x340 kernel/signal.c:1395 stack backtrace: CPU: 0 PID: 23176 Comm: syz.0.5186 Not tainted 6.10.0-rc7-syzkaller-00266-g4d145e3f830b #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 __lock_task_sighand+0xc2/0x340 kernel/signal.c:1412 lock_task_sighand include/linux/sched/signal.h:746 [inline] do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x290/0x300 kernel/signal.c:1451 bpf_send_signal_common+0x2e8/0x3a0 kernel/trace/bpf_trace.c:881 ____bpf_send_signal_thread kernel/trace/bpf_trace.c:898 [inline] bpf_send_signal_thread+0x16/0x20 kernel/trace/bpf_trace.c:896 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:2011 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2252 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline] bpf_trace_run4+0x245/0x5a0 kernel/trace/bpf_trace.c:2446 __bpf_trace_mmap_lock_acquire_returned+0x134/0x180 include/trace/events/mmap_lock.h:52 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline] __mmap_lock_do_trace_acquire_returned+0x456/0x790 mm/mmap_lock.c:237 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline] mmap_write_lock_killable include/linux/mmap_lock.h:123 [inline] __do_sys_munlock mm/mlock.c:697 [inline] __se_sys_munlock mm/mlock.c:688 [inline] __x64_sys_munlock+0x214/0x2c0 mm/mlock.c:688 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f323b975bd9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f323c7b9048 EFLAGS: 00000246 ORIG_RAX: 0000000000000096 RAX: ffffffffffffffda RBX: 00007f323bb03f60 RCX: 00007f323b975bd9 RDX: 0000000000000000 RSI: 0000000000001000 RDI: 0000000020cad000 RBP: 00007f323b9e4e60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f323bb03f60 R15: 00007fffba4043d8