================================ WARNING: inconsistent lock state syzkaller #0 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. syz.2.2355/13171 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff888026f6c130 (sk_lock-AF_X25){+.?.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline] ffff888026f6c130 (sk_lock-AF_X25){+.?.}-{0:0}, at: x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1782 {SOFTIRQ-ON-W} state was registered at: lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 lock_sock_nested+0x48/0x100 net/core/sock.c:3544 lock_sock include/net/sock.h:1780 [inline] x25_connect+0x5c/0x890 net/x25/af_x25.c:755 __sys_connect_file net/socket.c:2057 [inline] __sys_connect+0x3da/0x470 net/socket.c:2074 __do_sys_connect net/socket.c:2084 [inline] __se_sys_connect net/socket.c:2081 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2081 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 irq event stamp: 539630 hardirqs last enabled at (539630): [] __local_bh_enable_ip+0x13a/0x1c0 kernel/softirq.c:411 hardirqs last disabled at (539629): [] __local_bh_enable_ip+0xdb/0x1c0 kernel/softirq.c:388 softirqs last enabled at (535912): [] __do_softirq kernel/softirq.c:612 [inline] softirqs last enabled at (535912): [] invoke_softirq kernel/softirq.c:452 [inline] softirqs last enabled at (535912): [] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 softirqs last disabled at (539551): [] __do_softirq kernel/softirq.c:612 [inline] softirqs last disabled at (539551): [] invoke_softirq kernel/softirq.c:452 [inline] softirqs last disabled at (539551): [] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(sk_lock-AF_X25); lock(sk_lock-AF_X25); *** DEADLOCK *** 1 lock held by syz.2.2355/13171: #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: netif_receive_skb_core+0x34/0x230 net/core/dev.c:5670 stack backtrace: CPU: 1 PID: 13171 Comm: syz.2.2355 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 valid_state+0x13b/0x1d0 kernel/locking/lockdep.c:4013 mark_lock_irq+0xad/0x900 kernel/locking/lockdep.c:4216 mark_lock+0x208/0x320 kernel/locking/lockdep.c:4678 mark_usage kernel/locking/lockdep.c:-1 [inline] __lock_acquire+0xcfc/0x7d80 kernel/locking/lockdep.c:5091 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 lock_sock_nested+0x48/0x100 net/core/sock.c:3544 lock_sock include/net/sock.h:1780 [inline] x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1782 x25_lapb_receive_frame+0x1a7/0xef0 net/x25/x25_dev.c:138 __netif_receive_skb_one_core net/core/dev.c:5646 [inline] netif_receive_skb_core+0x16a/0x230 net/core/dev.c:5671 lapbeth_napi_poll+0x42/0x80 drivers/net/wan/lapbether.c:99 __napi_poll+0xbb/0x460 net/core/dev.c:6650 napi_poll net/core/dev.c:6717 [inline] net_rx_action+0x65f/0xcc0 net/core/dev.c:6853 handle_softirqs+0x27d/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:__kasan_check_read+0x0/0x20 mm/kasan/shadow.c:31 Code: 41 5c 41 5d 41 5e 41 5f 5d c3 48 c7 c7 59 58 a4 8c 4c 89 e6 eb 0a 48 c7 c7 bf ed 85 8c 48 89 de e8 d5 6d a1 08 31 ed eb d4 cc 0f 1e fa 89 f6 48 8b 0c 24 31 d2 e9 ff ea ff ff 66 2e 0f 1f 84 RSP: 0018:ffffc90004edf7f8 EFLAGS: 00000286 RAX: 0000000000000100 RBX: 1ffff1100ef1d616 RCX: ffffffff8167ed69 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8880778eb0b8 RBP: ffffc90004edf8a8 R08: ffff8880778eb0b7 R09: 1ffff1100ef1d616 R10: dffffc0000000000 R11: ffffed100ef1d617 R12: ffff8880778eb118 R13: 1ffff920009dbf04 R14: 1ffff1100ef1d623 R15: ffff8880778eb0b8 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_long_read include/linux/atomic/atomic-instrumented.h:3160 [inline] rwsem_test_oflags kernel/locking/rwsem.c:157 [inline] is_rwsem_reader_owned kernel/locking/rwsem.c:198 [inline] __up_read+0x140/0x6b0 kernel/locking/rwsem.c:1343 mmap_read_unlock include/linux/mmap_lock.h:173 [inline] do_user_addr_fault+0xcef/0x12d0 arch/x86/mm/fault.c:1399 handle_page_fault arch/x86/mm/fault.c:1463 [inline] exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0010:rep_movs_alternative+0x30/0x90 arch/x86/lib/copy_user_64.S:57 Code: f9 40 73 40 83 f9 08 73 21 85 c9 74 0f 8a 06 88 07 48 ff c7 48 ff c6 48 ff c9 75 f1 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 <48> 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 df 83 f9 08 RSP: 0018:ffffc90004edfa50 EFLAGS: 00050206 RAX: ffffffff84320801 RBX: 0000000000000038 RCX: 0000000000000038 RDX: 0000000000000001 RSI: 0000200000991000 RDI: ffffc90004edfae0 RBP: ffffc90004edfc70 R08: ffffc90004edfb17 R09: 1ffff920009dbf62 R10: dffffc0000000000 R11: fffff520009dbf63 R12: 0000200000991038 R13: ffffc90004edfae0 R14: ffffc90004edfae0 R15: 0000200000991000 copy_user_generic arch/x86/include/asm/uaccess_64.h:112 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:127 [inline] _copy_from_user+0x8b/0xe0 lib/usercopy.c:23 copy_from_user include/linux/uaccess.h:183 [inline] copy_msghdr_from_user net/socket.c:2525 [inline] recvmsg_copy_msghdr net/socket.c:2780 [inline] ___sys_recvmsg+0x174/0x590 net/socket.c:2852 do_recvmmsg+0x377/0x810 net/socket.c:2950 __sys_recvmmsg net/socket.c:3029 [inline] __do_sys_recvmmsg net/socket.c:3052 [inline] __se_sys_recvmmsg net/socket.c:3045 [inline] __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3045 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1277b9e0d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1278aca028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f1277e26090 RCX: 00007f1277b9e0d9 RDX: 03fffffffffffcb5 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007f1277c35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1277e26128 R14: 00007f1277e26090 R15: 00007ffebf3cb958 BUG: sleeping function called from invalid context at net/core/sock.c:3546 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 13171, name: syz.2.2355 preempt_count: 100, expected: 0 RCU nest depth: 1, expected: 0 INFO: lockdep is turned off. Preemption disabled at: [] softirq_handle_begin kernel/softirq.c:419 [inline] [] handle_softirqs+0x101/0x820 kernel/softirq.c:554 CPU: 1 PID: 13171 Comm: syz.2.2355 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 __might_resched+0x48d/0x5f0 kernel/sched/core.c:10212 lock_sock_nested+0x5d/0x100 net/core/sock.c:3546 lock_sock include/net/sock.h:1780 [inline] x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1782 x25_lapb_receive_frame+0x1a7/0xef0 net/x25/x25_dev.c:138 __netif_receive_skb_one_core net/core/dev.c:5646 [inline] netif_receive_skb_core+0x16a/0x230 net/core/dev.c:5671 lapbeth_napi_poll+0x42/0x80 drivers/net/wan/lapbether.c:99 __napi_poll+0xbb/0x460 net/core/dev.c:6650 napi_poll net/core/dev.c:6717 [inline] net_rx_action+0x65f/0xcc0 net/core/dev.c:6853 handle_softirqs+0x27d/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:__kasan_check_read+0x0/0x20 mm/kasan/shadow.c:31 Code: 41 5c 41 5d 41 5e 41 5f 5d c3 48 c7 c7 59 58 a4 8c 4c 89 e6 eb 0a 48 c7 c7 bf ed 85 8c 48 89 de e8 d5 6d a1 08 31 ed eb d4 cc 0f 1e fa 89 f6 48 8b 0c 24 31 d2 e9 ff ea ff ff 66 2e 0f 1f 84 RSP: 0018:ffffc90004edf7f8 EFLAGS: 00000286 RAX: 0000000000000100 RBX: 1ffff1100ef1d616 RCX: ffffffff8167ed69 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8880778eb0b8 RBP: ffffc90004edf8a8 R08: ffff8880778eb0b7 R09: 1ffff1100ef1d616 R10: dffffc0000000000 R11: ffffed100ef1d617 R12: ffff8880778eb118 R13: 1ffff920009dbf04 R14: 1ffff1100ef1d623 R15: ffff8880778eb0b8 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_long_read include/linux/atomic/atomic-instrumented.h:3160 [inline] rwsem_test_oflags kernel/locking/rwsem.c:157 [inline] is_rwsem_reader_owned kernel/locking/rwsem.c:198 [inline] __up_read+0x140/0x6b0 kernel/locking/rwsem.c:1343 mmap_read_unlock include/linux/mmap_lock.h:173 [inline] do_user_addr_fault+0xcef/0x12d0 arch/x86/mm/fault.c:1399 handle_page_fault arch/x86/mm/fault.c:1463 [inline] exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0010:rep_movs_alternative+0x30/0x90 arch/x86/lib/copy_user_64.S:57 Code: f9 40 73 40 83 f9 08 73 21 85 c9 74 0f 8a 06 88 07 48 ff c7 48 ff c6 48 ff c9 75 f1 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 <48> 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 df 83 f9 08 RSP: 0018:ffffc90004edfa50 EFLAGS: 00050206 RAX: ffffffff84320801 RBX: 0000000000000038 RCX: 0000000000000038 RDX: 0000000000000001 RSI: 0000200000991000 RDI: ffffc90004edfae0 RBP: ffffc90004edfc70 R08: ffffc90004edfb17 R09: 1ffff920009dbf62 R10: dffffc0000000000 R11: fffff520009dbf63 R12: 0000200000991038 R13: ffffc90004edfae0 R14: ffffc90004edfae0 R15: 0000200000991000 copy_user_generic arch/x86/include/asm/uaccess_64.h:112 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:127 [inline] _copy_from_user+0x8b/0xe0 lib/usercopy.c:23 copy_from_user include/linux/uaccess.h:183 [inline] copy_msghdr_from_user net/socket.c:2525 [inline] recvmsg_copy_msghdr net/socket.c:2780 [inline] ___sys_recvmsg+0x174/0x590 net/socket.c:2852 do_recvmmsg+0x377/0x810 net/socket.c:2950 __sys_recvmmsg net/socket.c:3029 [inline] __do_sys_recvmmsg net/socket.c:3052 [inline] __se_sys_recvmmsg net/socket.c:3045 [inline] __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3045 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1277b9e0d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1278aca028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f1277e26090 RCX: 00007f1277b9e0d9 RDX: 03fffffffffffcb5 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007f1277c35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1277e26128 R14: 00007f1277e26090 R15: 00007ffebf3cb958 ---------------- Code disassembly (best guess): 0: 41 5c pop %r12 2: 41 5d pop %r13 4: 41 5e pop %r14 6: 41 5f pop %r15 8: 5d pop %rbp 9: c3 ret a: 48 c7 c7 59 58 a4 8c mov $0xffffffff8ca45859,%rdi 11: 4c 89 e6 mov %r12,%rsi 14: eb 0a jmp 0x20 16: 48 c7 c7 bf ed 85 8c mov $0xffffffff8c85edbf,%rdi 1d: 48 89 de mov %rbx,%rsi 20: e8 d5 6d a1 08 call 0x8a16dfa 25: 31 ed xor %ebp,%ebp 27: eb d4 jmp 0xfffffffd 29: cc int3 * 2a: f3 0f 1e fa endbr64 <-- trapping instruction 2e: 89 f6 mov %esi,%esi 30: 48 8b 0c 24 mov (%rsp),%rcx 34: 31 d2 xor %edx,%edx 36: e9 ff ea ff ff jmp 0xffffeb3a 3b: 66 data16 3c: 2e cs 3d: 0f .byte 0xf 3e: 1f (bad) 3f: 84 .byte 0x84