====================================================== WARNING: possible circular locking dependency detected 6.10.0-syzkaller-04483-g0be9ae5486cd #0 Not tainted ------------------------------------------------------ syz.4.2967/13420 is trying to acquire lock: ffff88802941d358 (&sighand->siglock){-.-.}-{2:2}, at: __lock_task_sighand+0x149/0x2d0 kernel/signal.c:1412 but task is already holding lock: ffff8880b9538798 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b9538798 (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:5753 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:164 [inline] stack_map_get_build_id_offset+0x9af/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:1997 [inline] bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1987 0xffffffffa0004a9a 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:2406 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2447 trace_tlb_flush+0x118/0x140 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x7cb/0xae0 context_switch kernel/sched/core.c:5172 [inline] __schedule+0x1079/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 do_nanosleep+0x197/0x600 kernel/time/hrtimer.c:2030 hrtimer_nanosleep+0x227/0x470 kernel/time/hrtimer.c:2083 __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+0xf3/0x230 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:5753 _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:560 raw_spin_rq_lock kernel/sched/sched.h:1415 [inline] _raw_spin_rq_lock_irqsave kernel/sched/sched.h:1435 [inline] rq_lock_irqsave kernel/sched/sched.h:1700 [inline] class_rq_lock_irqsave_constructor kernel/sched/sched.h:1749 [inline] sched_mm_cid_exit_signals+0x17b/0x4b0 kernel/sched/core.c:10245 exit_signals+0x2a1/0x5c0 kernel/signal.c:3022 do_exit+0x6b4/0x27f0 kernel/exit.c:834 __do_sys_exit kernel/exit.c:993 [inline] __se_sys_exit kernel/exit.c:991 [inline] __pfx___ia32_sys_exit+0x0/0x10 kernel/exit.c:991 x64_sys_call+0x2622/0x2640 arch/x86/include/generated/asm/syscalls_64.h:61 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 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:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5136 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5753 __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+0x149/0x2d0 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+0x274/0x310 kernel/signal.c:1451 bpf_send_signal_common+0x2dd/0x430 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_7bb747c56a8bcba8+0x1d/0x25 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:2406 [inline] bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2449 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_read_trylock include/linux/mmap_lock.h:164 [inline] get_mmap_lock_carefully mm/memory.c:5716 [inline] lock_mm_and_find_vma+0x213/0x2f0 mm/memory.c:5776 do_user_addr_fault arch/x86/mm/fault.c:1361 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x1bf/0x8c0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 strncpy_from_user+0x110/0x2e0 lib/strncpy_from_user.c:139 bpf_prog_load+0xd65/0x20f0 kernel/bpf/syscall.c:2849 __sys_bpf+0x4ee/0x810 kernel/bpf/syscall.c:5710 __do_sys_bpf kernel/bpf/syscall.c:5817 [inline] __se_sys_bpf kernel/bpf/syscall.c:5815 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5815 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 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.4.2967/13420: #0: ffff88804c1acd98 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:163 [inline] #0: ffff88804c1acd98 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5716 [inline] #0: ffff88804c1acd98 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5776 #1: ffff8880b9538798 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #1: ffff8880b9538798 (lock#10){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237 #2: ffffffff8e335fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:327 [inline] #2: ffffffff8e335fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:839 [inline] #2: ffffffff8e335fe0 (rcu_read_lock){....}-{1:2}, at: get_memcg_path_buf mm/mmap_lock.c:139 [inline] #2: ffffffff8e335fe0 (rcu_read_lock){....}-{1:2}, at: get_mm_memcg_path+0xb1/0x600 mm/mmap_lock.c:209 #3: ffffffff8e335fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:327 [inline] #3: ffffffff8e335fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:839 [inline] #3: ffffffff8e335fe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline] #3: ffffffff8e335fe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x244/0x590 kernel/trace/bpf_trace.c:2449 #4: ffffffff8e335fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:327 [inline] #4: ffffffff8e335fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:839 [inline] #4: ffffffff8e335fe0 (rcu_read_lock){....}-{1:2}, at: __lock_task_sighand+0x29/0x2d0 kernel/signal.c:1395 stack backtrace: CPU: 1 PID: 13420 Comm: syz.4.2967 Not tainted 6.10.0-syzkaller-04483-g0be9ae5486cd #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+0x241/0x360 lib/dump_stack.c:114 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2186 check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5136 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5753 __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+0x149/0x2d0 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+0x274/0x310 kernel/signal.c:1451 bpf_send_signal_common+0x2dd/0x430 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_7bb747c56a8bcba8+0x1d/0x25 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:2406 [inline] bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2449 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_read_trylock include/linux/mmap_lock.h:164 [inline] get_mmap_lock_carefully mm/memory.c:5716 [inline] lock_mm_and_find_vma+0x213/0x2f0 mm/memory.c:5776 do_user_addr_fault arch/x86/mm/fault.c:1361 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x1bf/0x8c0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] RIP: 0010:strncpy_from_user+0x110/0x2e0 lib/strncpy_from_user.c:139 Code: 00 00 00 4c 89 e6 e8 df 27 ad fc 49 83 fc 07 0f 86 9a 00 00 00 48 89 6c 24 08 48 c7 44 24 10 f8 ff ff ff 45 31 ed 4c 89 3c 24 <4f> 8b 3c 2f 48 b8 ff fe fe fe fe fe fe fe 49 8d 1c 07 4c 89 fd 48 RSP: 0018:ffffc90012cbfb10 EFLAGS: 00050246 RAX: 0000000000000002 RBX: ffffc90012cbfdb0 RCX: ffff888064c59e00 RDX: ffffc90014801000 RSI: 000000000000007f RDI: 0000000000000007 RBP: 000000000000007f R08: ffffffff84e93901 R09: ffffffff820ad4c7 R10: 0000000000000003 R11: ffff888064c59e00 R12: 000000000000007f R13: 0000000000000000 R14: ffffc90012cbfc50 R15: 0000000000000000 bpf_prog_load+0xd65/0x20f0 kernel/bpf/syscall.c:2849 __sys_bpf+0x4ee/0x810 kernel/bpf/syscall.c:5710 __do_sys_bpf kernel/bpf/syscall.c:5817 [inline] __se_sys_bpf kernel/bpf/syscall.c:5815 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5815 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f74dd975b59 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:00007f74de6f2048 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f74ddb05f60 RCX: 00007f74dd975b59 RDX: 0000000000000090 RSI: 0000000020000140 RDI: 0000000000000005 RBP: 00007f74dd9e4e5d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f74ddb05f60 R15: 00007ffc8d8573d8 netlink: 60 bytes leftover after parsing attributes in process `syz.4.2967'. ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 4c 89 e6 add %cl,-0x1a(%rcx,%rcx,4) 6: e8 df 27 ad fc call 0xfcad27ea b: 49 83 fc 07 cmp $0x7,%r12 f: 0f 86 9a 00 00 00 jbe 0xaf 15: 48 89 6c 24 08 mov %rbp,0x8(%rsp) 1a: 48 c7 44 24 10 f8 ff movq $0xfffffffffffffff8,0x10(%rsp) 21: ff ff 23: 45 31 ed xor %r13d,%r13d 26: 4c 89 3c 24 mov %r15,(%rsp) * 2a: 4f 8b 3c 2f mov (%r15,%r13,1),%r15 <-- trapping instruction 2e: 48 b8 ff fe fe fe fe movabs $0xfefefefefefefeff,%rax 35: fe fe fe 38: 49 8d 1c 07 lea (%r15,%rax,1),%rbx 3c: 4c 89 fd mov %r15,%rbp 3f: 48 rex.W