====================================================== WARNING: possible circular locking dependency detected 6.10.0-rc2-syzkaller-00235-g93792130a938 #0 Not tainted ------------------------------------------------------ syz-executor.3/15350 is trying to acquire lock: ffff8880b9538828 (lock#10){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b9538828 (lock#10){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237 but task is already holding lock: ffff8880b953e7d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&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: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_exit_signals+0x17b/0x4b0 kernel/sched/core.c:12004 exit_signals+0x2a1/0x5c0 kernel/signal.c:3014 do_exit+0x6b4/0x27e0 kernel/exit.c:833 __do_sys_exit kernel/exit.c:990 [inline] __se_sys_exit kernel/exit.c:988 [inline] __pfx___ia32_sys_exit+0x0/0x10 kernel/exit.c:988 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 (&sighand->siglock){-...}-{2:2}: 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+0x149/0x2d0 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 0xffffffffa000088a 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_read_trylock include/linux/mmap_lock.h:164 [inline] get_mmap_lock_carefully mm/memory.c:5715 [inline] lock_mm_and_find_vma+0x213/0x2f0 mm/memory.c:5775 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+0x110/0x2f0 lib/strncpy_from_user.c:139 bpf_prog_load+0xd65/0x20f0 kernel/bpf/syscall.c:2849 __sys_bpf+0x4ee/0x810 kernel/bpf/syscall.c:5688 __do_sys_bpf kernel/bpf/syscall.c:5795 [inline] __se_sys_bpf kernel/bpf/syscall.c:5793 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5793 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 (lock#10){+.+.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 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: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: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:5392 [inline] __schedule+0x1066/0x4a20 kernel/sched/core.c:6745 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6924 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6948 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __mmap_lock_do_trace_acquire_returned+0x319/0x630 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:5715 [inline] lock_mm_and_find_vma+0x213/0x2f0 mm/memory.c:5775 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 rep_movs_alternative+0x4a/0x70 arch/x86/lib/copy_user_64.S:65 copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:125 [inline] copy_from_user_iter lib/iov_iter.c:55 [inline] iterate_ubuf include/linux/iov_iter.h:29 [inline] iterate_and_advance2 include/linux/iov_iter.h:245 [inline] iterate_and_advance include/linux/iov_iter.h:271 [inline] __copy_from_iter lib/iov_iter.c:249 [inline] _copy_from_iter+0x26b/0x1960 lib/iov_iter.c:260 copy_from_iter include/linux/uio.h:204 [inline] copy_from_iter_full include/linux/uio.h:221 [inline] memcpy_from_msg include/linux/skbuff.h:4035 [inline] netlink_sendmsg+0x743/0xcb0 net/netlink/af_netlink.c:1890 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 sock_write_iter+0x2dd/0x400 net/socket.c:1160 new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa72/0xc90 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 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: lock#10 --> &sighand->siglock --> &rq->__lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->__lock); lock(&sighand->siglock); lock(&rq->__lock); lock(lock#10); *** DEADLOCK *** 4 locks held by syz-executor.3/15350: #0: ffff88802fe8e098 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:163 [inline] #0: ffff88802fe8e098 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5715 [inline] #0: ffff88802fe8e098 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5775 #1: ffff8880b953e7d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 #2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2402 [inline] #2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2444 #3: ffff88802fe8e098 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:163 [inline] #3: ffff88802fe8e098 (&mm->mmap_lock){++++}-{3:3}, at: stack_map_get_build_id_offset+0x237/0x9d0 kernel/bpf/stackmap.c:141 stack backtrace: CPU: 1 PID: 15350 Comm: syz-executor.3 Not tainted 6.10.0-rc2-syzkaller-00235-g93792130a938 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 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+0x18e0/0x5900 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 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: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: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:5392 [inline] __schedule+0x1066/0x4a20 kernel/sched/core.c:6745 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6924 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6948 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __mmap_lock_do_trace_acquire_returned+0x319/0x630 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:5715 [inline] lock_mm_and_find_vma+0x213/0x2f0 mm/memory.c:5775 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:rep_movs_alternative+0x4a/0x70 arch/x86/lib/copy_user_64.S:71 Code: 75 f1 c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 df 83 f9 08 73 e8 eb c9 a4 c3 cc cc cc cc 48 89 c8 48 c1 e9 03 83 e0 07 f3 48 a5 89 c1 RSP: 0018:ffffc900034cf858 EFLAGS: 00050206 RAX: ffffffff84ad2a01 RBX: 000000000000fe33 RCX: 000000000000ee33 RDX: 0000000000000001 RSI: 0000000020001000 RDI: ffff8880688e1000 RBP: ffffc900034cf9d0 R08: ffff8880688efe32 R09: 1ffff1100d11dfc6 R10: dffffc0000000000 R11: ffffed100d11dfc7 R12: 1ffff92000699f77 R13: 0000000020000000 R14: ffffc900034cfbb8 R15: ffff8880688e0000 copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:125 [inline] copy_from_user_iter lib/iov_iter.c:55 [inline] iterate_ubuf include/linux/iov_iter.h:29 [inline] iterate_and_advance2 include/linux/iov_iter.h:245 [inline] iterate_and_advance include/linux/iov_iter.h:271 [inline] __copy_from_iter lib/iov_iter.c:249 [inline] _copy_from_iter+0x26b/0x1960 lib/iov_iter.c:260 copy_from_iter include/linux/uio.h:204 [inline] copy_from_iter_full include/linux/uio.h:221 [inline] memcpy_from_msg include/linux/skbuff.h:4035 [inline] netlink_sendmsg+0x743/0xcb0 net/netlink/af_netlink.c:1890 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 sock_write_iter+0x2dd/0x400 net/socket.c:1160 new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa72/0xc90 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 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: 0033:0x7f91b047cf69 Code: Unable to access opcode bytes at 0x7f91b047cf3f. RSP: 002b:00007f91affff0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f91b05b3f80 RCX: 00007f91b047cf69 RDX: 000000000000fe33 RSI: 0000000020000000 RDI: 0000000000000006 RBP: 00007f91b04da6fe R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f91b05b3f80 R15: 00007ffcd7678658 netlink: 9286 bytes leftover after parsing attributes in process `syz-executor.3'. ---------------- Code disassembly (best guess): 0: 75 f1 jne 0xfffffff3 2: c3 ret 3: cc int3 4: cc int3 5: cc int3 6: cc int3 7: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1) e: 00 00 10: 48 8b 06 mov (%rsi),%rax 13: 48 89 07 mov %rax,(%rdi) 16: 48 83 c6 08 add $0x8,%rsi 1a: 48 83 c7 08 add $0x8,%rdi 1e: 83 e9 08 sub $0x8,%ecx 21: 74 df je 0x2 23: 83 f9 08 cmp $0x8,%ecx 26: 73 e8 jae 0x10 28: eb c9 jmp 0xfffffff3 * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: c3 ret 2d: cc int3 2e: cc int3 2f: cc int3 30: cc int3 31: 48 89 c8 mov %rcx,%rax 34: 48 c1 e9 03 shr $0x3,%rcx 38: 83 e0 07 and $0x7,%eax 3b: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi) 3e: 89 c1 mov %eax,%ecx