====================================================== WARNING: possible circular locking dependency detected 6.9.0-rc5-syzkaller-01452-ga9e7715ce8b3 #0 Not tainted ------------------------------------------------------ syz-executor.4/5460 is trying to acquire lock: ffff88807be98018 (&sighand->siglock){-...}-{2:2}, at: __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414 but task is already holding lock: ffff8880b95387e8 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b95387e8 (lock#10){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (lock#10){+.+.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_acquire_returned+0xa8/0x630 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:166 [inline] stack_map_get_build_id_offset+0x9b2/0x9d0 kernel/bpf/stackmap.c:141 __bpf_get_stack+0x4ad/0x5a0 kernel/bpf/stackmap.c:449 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1994 [inline] bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1984 bpf_prog_ec3b2eefa702d8d3+0x42/0x46 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+0x2ec/0x540 kernel/trace/bpf_trace.c:2444 trace_tlb_flush+0x118/0x140 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x7cb/0xae0 context_switch kernel/sched/core.c:5393 [inline] __schedule+0x1066/0x4a50 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 do_nanosleep+0x197/0x600 kernel/time/hrtimer.c:2051 hrtimer_nanosleep+0x227/0x470 kernel/time/hrtimer.c:2104 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1396 [inline] __se_sys_clock_nanosleep+0x32b/0x3c0 kernel/time/posix-timers.c:1373 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 raw_spin_rq_lock kernel/sched/sched.h:1387 [inline] _raw_spin_rq_lock_irqsave kernel/sched/sched.h:1406 [inline] rq_lock_irqsave kernel/sched/sched.h:1685 [inline] class_rq_lock_irqsave_constructor kernel/sched/sched.h:1739 [inline] sched_mm_cid_exit_signals+0x17b/0x4b0 kernel/sched/core.c:12005 exit_signals+0x2a1/0x5c0 kernel/signal.c:3016 do_exit+0x6a8/0x27e0 kernel/exit.c:837 __do_sys_exit kernel/exit.c:994 [inline] __se_sys_exit kernel/exit.c:992 [inline] __pfx___ia32_sys_exit+0x0/0x10 kernel/exit.c:992 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 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+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414 lock_task_sighand include/linux/sched/signal.h:746 [inline] do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x274/0x310 kernel/signal.c:1453 bpf_send_signal_common+0x2dd/0x430 kernel/trace/bpf_trace.c:881 ____bpf_send_signal kernel/trace/bpf_trace.c:886 [inline] bpf_send_signal+0x19/0x30 kernel/trace/bpf_trace.c:884 bpf_prog_9fbc3d1d47c9b36c+0x22/0x29 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+0x334/0x590 kernel/trace/bpf_trace.c:2446 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline] __mmap_lock_do_trace_acquire_returned+0x5c8/0x630 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:125 [inline] vm_mmap_pgoff+0x3e8/0x420 mm/util.c:571 ksys_mmap_pgoff+0x504/0x6e0 mm/mmap.c:1431 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 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#10 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#10); lock(&rq->__lock); lock(lock#10); lock(&sighand->siglock); *** DEADLOCK *** 5 locks held by syz-executor.4/5460: #0: ffff8880117594a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline] #0: ffff8880117594a0 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x182/0x420 mm/util.c:571 #1: ffff8880b95387e8 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #1: ffff8880b95387e8 (lock#10){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237 #2: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #2: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #2: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: get_memcg_path_buf mm/mmap_lock.c:139 [inline] #2: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: get_mm_memcg_path+0xb1/0x600 mm/mmap_lock.c:209 #3: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #3: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x244/0x590 kernel/trace/bpf_trace.c:2446 #4: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #4: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #4: ffffffff8e334e20 (rcu_read_lock){....}-{1:2}, at: __lock_task_sighand+0x29/0x2e0 kernel/signal.c:1397 stack backtrace: CPU: 1 PID: 5460 Comm: syz-executor.4 Not tainted 6.9.0-rc5-syzkaller-01452-ga9e7715ce8b3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x36a/0x4a0 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+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414 lock_task_sighand include/linux/sched/signal.h:746 [inline] do_send_sig_info kernel/signal.c:1300 [inline] group_send_sig_info+0x274/0x310 kernel/signal.c:1453 bpf_send_signal_common+0x2dd/0x430 kernel/trace/bpf_trace.c:881 ____bpf_send_signal kernel/trace/bpf_trace.c:886 [inline] bpf_send_signal+0x19/0x30 kernel/trace/bpf_trace.c:884 bpf_prog_9fbc3d1d47c9b36c+0x22/0x29 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+0x334/0x590 kernel/trace/bpf_trace.c:2446 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline] __mmap_lock_do_trace_acquire_returned+0x5c8/0x630 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:125 [inline] vm_mmap_pgoff+0x3e8/0x420 mm/util.c:571 ksys_mmap_pgoff+0x504/0x6e0 mm/mmap.c:1431 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4debe7dce3 Code: f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 41 89 ca 41 f7 c1 ff 0f 00 00 75 14 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 25 c3 0f 1f 40 00 48 c7 c0 b0 ff ff ff 64 c7 RSP: 002b:00007ffef8ed4be8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000000000400000 RCX: 00007f4debe7dce3 RDX: 0000000000000003 RSI: 00000000003c0000 RDI: 0000001b31f60000 RBP: 0000001b31f60000 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001