================================ WARNING: inconsistent lock state syzkaller #0 Tainted: G L -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. syz.8.6700/29413 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff88807df2e260 (sk_lock-AF_X25){+.?.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] ffff88807df2e260 (sk_lock-AF_X25){+.?.}-{0:0}, at: x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1778 {SOFTIRQ-ON-W} state was registered at: lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908 lock_sock_nested+0x41/0x100 net/core/sock.c:3827 lock_sock include/net/sock.h:1713 [inline] x25_release+0xa0/0x3d0 net/x25/af_x25.c:632 __sock_release+0xa0/0x1f0 net/socket.c:735 sock_close+0x1c/0x30 net/socket.c:1526 __fput+0x418/0xa50 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1fa/0x750 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline] do_syscall_64+0x328/0x510 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f irq event stamp: 51848 hardirqs last enabled at (51848): [] __local_bh_enable_ip+0xd0/0x130 kernel/softirq.c:457 hardirqs last disabled at (51847): [] __local_bh_enable_ip+0x71/0x130 kernel/softirq.c:434 softirqs last enabled at (48026): [] __do_softirq kernel/softirq.c:658 [inline] softirqs last enabled at (48026): [] invoke_softirq kernel/softirq.c:498 [inline] softirqs last enabled at (48026): [] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:737 softirqs last disabled at (51757): [] __do_softirq kernel/softirq.c:658 [inline] softirqs last disabled at (51757): [] invoke_softirq kernel/softirq.c:498 [inline] softirqs last disabled at (51757): [] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:737 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(sk_lock-AF_X25); lock(sk_lock-AF_X25); *** DEADLOCK *** locks held by syz.8.6700/29413: 1, last CPU#1: #0: ffffffff8eb5c820 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8eb5c820 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8eb5c820 (rcu_read_lock){....}-{1:3}, at: netif_receive_skb_core+0x33/0x2b0 net/core/dev.c:6269 stack backtrace: CPU: 1 UID: 0 PID: 29413 Comm: syz.8.6700 Tainted: G L syzkaller #0 PREEMPT(lazy) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_usage_bug+0x28b/0x2e0 kernel/locking/lockdep.c:4058 valid_state+0xbe/0xf0 kernel/locking/lockdep.c:4072 mark_lock_irq+0x36/0x380 kernel/locking/lockdep.c:4283 mark_lock+0x117/0x190 kernel/locking/lockdep.c:4769 mark_usage kernel/locking/lockdep.c:-1 [inline] __lock_acquire+0x6b7/0x2e50 kernel/locking/lockdep.c:5208 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908 lock_sock_nested+0x41/0x100 net/core/sock.c:3827 lock_sock include/net/sock.h:1713 [inline] x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1778 x25_lapb_receive_frame+0x1b0/0xfb0 net/x25/x25_dev.c:138 __netif_receive_skb_one_core net/core/dev.c:6245 [inline] netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6270 lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100 __napi_poll+0xaa/0x330 net/core/dev.c:7768 napi_poll net/core/dev.c:7831 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7988 handle_softirqs+0x225/0x840 kernel/softirq.c:624 __do_softirq kernel/softirq.c:658 [inline] invoke_softirq kernel/softirq.c:498 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:737 irq_exit_rcu+0x9/0x30 kernel/softirq.c:754 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:37 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:139 [inline] RIP: 0010:wrmsrq arch/x86/include/asm/msr.h:199 [inline] RIP: 0010:native_x2apic_icr_write arch/x86/include/asm/apic.h:229 [inline] RIP: 0010:__x2apic_send_IPI_dest arch/x86/kernel/apic/local.h:47 [inline] RIP: 0010:x2apic_send_IPI+0x73/0xd0 arch/x86/kernel/apic/x2apic_phys.c:50 Code: 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 75 3b 41 8b 16 0f ae f0 0f ae e8 83 fb 02 b8 00 04 00 00 0f 45 c3 b9 30 08 00 00 0f 30 <66> 90 5b 41 5c 41 5e 41 5f e9 bf a9 67 0a cc 48 c7 c7 20 71 9b 8e RSP: 0018:ffffc90005a1f8f8 EFLAGS: 00000206 RAX: 00000000000000fb RBX: 00000000000000fb RCX: 0000000000000830 RDX: 0000000000000000 RSI: 00000000000000fb RDI: 0000000000000000 RBP: ffffc90005a1f9e0 R08: ffffffff9058fd7f R09: 1ffffffff20b1faf R10: dffffc0000000000 R11: ffffffff81754110 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff8880b86201d8 R15: ffffffff8e5257d0 arch_send_call_function_single_ipi arch/x86/include/asm/smp.h:95 [inline] send_call_function_single_ipi kernel/smp.c:127 [inline] __smp_call_single_queue+0x1e2/0x4a0 kernel/smp.c:468 generic_exec_single+0x16d/0x3c0 kernel/smp.c:505 smp_call_function_single_async+0x79/0x110 kernel/smp.c:807 rdmsrq_safe_on_cpu+0x163/0x240 arch/x86/lib/msr-smp.c:163 msr_read+0x13a/0x230 arch/x86/kernel/msr.c:69 vfs_read+0x213/0xa80 fs/read_write.c:572 ksys_read+0x150/0x270 fs/read_write.c:716 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x510 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f591e79e0d9 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:00007f591f5a8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f591ea25fa0 RCX: 00007f591e79e0d9 RDX: 0000000000018ff8 RSI: 0000200000019680 RDI: 0000000000000007 RBP: 00007f591e835024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f591ea26038 R14: 00007f591ea25fa0 R15: 00007ffc283e8048 BUG: sleeping function called from invalid context at net/core/sock.c:3829 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 29413, name: syz.8.6700 preempt_count: 101, expected: 0 RCU nest depth: 1, expected: 0 INFO: lockdep is turned off. Preemption disabled at: [] smp_call_function_single_async+0x2c/0x110 kernel/smp.c:797 CPU: 1 UID: 0 PID: 29413 Comm: syz.8.6700 Tainted: G L syzkaller #0 PREEMPT(lazy) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 __might_resched+0x378/0x4d0 kernel/sched/core.c:9195 lock_sock_nested+0x56/0x100 net/core/sock.c:3829 lock_sock include/net/sock.h:1713 [inline] x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1778 x25_lapb_receive_frame+0x1b0/0xfb0 net/x25/x25_dev.c:138 __netif_receive_skb_one_core net/core/dev.c:6245 [inline] netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6270 lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100 __napi_poll+0xaa/0x330 net/core/dev.c:7768 napi_poll net/core/dev.c:7831 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7988 handle_softirqs+0x225/0x840 kernel/softirq.c:624 __do_softirq kernel/softirq.c:658 [inline] invoke_softirq kernel/softirq.c:498 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:737 irq_exit_rcu+0x9/0x30 kernel/softirq.c:754 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:37 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:139 [inline] RIP: 0010:wrmsrq arch/x86/include/asm/msr.h:199 [inline] RIP: 0010:native_x2apic_icr_write arch/x86/include/asm/apic.h:229 [inline] RIP: 0010:__x2apic_send_IPI_dest arch/x86/kernel/apic/local.h:47 [inline] RIP: 0010:x2apic_send_IPI+0x73/0xd0 arch/x86/kernel/apic/x2apic_phys.c:50 Code: 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 75 3b 41 8b 16 0f ae f0 0f ae e8 83 fb 02 b8 00 04 00 00 0f 45 c3 b9 30 08 00 00 0f 30 <66> 90 5b 41 5c 41 5e 41 5f e9 bf a9 67 0a cc 48 c7 c7 20 71 9b 8e RSP: 0018:ffffc90005a1f8f8 EFLAGS: 00000206 RAX: 00000000000000fb RBX: 00000000000000fb RCX: 0000000000000830 RDX: 0000000000000000 RSI: 00000000000000fb RDI: 0000000000000000 RBP: ffffc90005a1f9e0 R08: ffffffff9058fd7f R09: 1ffffffff20b1faf R10: dffffc0000000000 R11: ffffffff81754110 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff8880b86201d8 R15: ffffffff8e5257d0 arch_send_call_function_single_ipi arch/x86/include/asm/smp.h:95 [inline] send_call_function_single_ipi kernel/smp.c:127 [inline] __smp_call_single_queue+0x1e2/0x4a0 kernel/smp.c:468 generic_exec_single+0x16d/0x3c0 kernel/smp.c:505 smp_call_function_single_async+0x79/0x110 kernel/smp.c:807 rdmsrq_safe_on_cpu+0x163/0x240 arch/x86/lib/msr-smp.c:163 msr_read+0x13a/0x230 arch/x86/kernel/msr.c:69 vfs_read+0x213/0xa80 fs/read_write.c:572 ksys_read+0x150/0x270 fs/read_write.c:716 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x510 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f591e79e0d9 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:00007f591f5a8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f591ea25fa0 RCX: 00007f591e79e0d9 RDX: 0000000000018ff8 RSI: 0000200000019680 RDI: 0000000000000007 RBP: 00007f591e835024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f591ea26038 R14: 00007f591ea25fa0 R15: 00007ffc283e8048 ---------------- Code disassembly (best guess): 0: 89 f0 mov %esi,%eax 2: 48 c1 e8 03 shr $0x3,%rax 6: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax b: 84 c0 test %al,%al d: 75 3b jne 0x4a f: 41 8b 16 mov (%r14),%edx 12: 0f ae f0 mfence 15: 0f ae e8 lfence 18: 83 fb 02 cmp $0x2,%ebx 1b: b8 00 04 00 00 mov $0x400,%eax 20: 0f 45 c3 cmovne %ebx,%eax 23: b9 30 08 00 00 mov $0x830,%ecx 28: 0f 30 wrmsr * 2a: 66 90 xchg %ax,%ax <-- trapping instruction 2c: 5b pop %rbx 2d: 41 5c pop %r12 2f: 41 5e pop %r14 31: 41 5f pop %r15 33: e9 bf a9 67 0a jmp 0xa67a9f7 38: cc int3 39: 48 c7 c7 20 71 9b 8e mov $0xffffffff8e9b7120,%rdi