================================ WARNING: inconsistent lock state syzkaller #0 Tainted: G L -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. syz.8.4888/26903 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff88807beec260 (sk_lock-AF_X25){+.?.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] ffff88807beec260 (sk_lock-AF_X25){+.?.}-{0:0}, at: x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1775 {SOFTIRQ-ON-W} state was registered at: lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 lock_sock_nested+0x41/0x100 net/core/sock.c:3837 lock_sock include/net/sock.h:1713 [inline] x25_release+0xa0/0x3d0 net/x25/af_x25.c:629 __sock_release+0xa0/0x1f0 net/socket.c:735 sock_close+0x1c/0x30 net/socket.c:1526 __fput+0x413/0xa50 fs/file_table.c:513 fput_close_sync+0x11f/0x240 fs/file_table.c:618 filp_close_sync+0x6e/0xa0 fs/open.c:1573 close_files fs/file.c:572 [inline] put_files_struct+0x230/0x3c0 fs/file.c:584 do_exit+0x6f0/0x2380 kernel/exit.c:977 do_group_exit+0x22d/0x2f0 kernel/exit.c:1123 get_signal+0x1216/0x12c0 kernel/signal.c:3112 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x10e/0x770 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:343 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f irq event stamp: 154280 hardirqs last enabled at (154280): [] __local_bh_enable_ip+0xd6/0x140 kernel/softirq.c:478 hardirqs last disabled at (154279): [] __local_bh_enable_ip+0x72/0x140 kernel/softirq.c:455 softirqs last enabled at (150084): [] __do_softirq kernel/softirq.c:679 [inline] softirqs last enabled at (150084): [] invoke_softirq kernel/softirq.c:519 [inline] softirqs last enabled at (150084): [] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758 softirqs last disabled at (154177): [] __do_softirq kernel/softirq.c:679 [inline] softirqs last disabled at (154177): [] invoke_softirq kernel/softirq.c:519 [inline] softirqs last disabled at (154177): [] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758 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.8.4888/26903: 3, last CPU#0: #0: ffff88807767e460 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0xb41/0x10f0 fs/coredump.c:1306 #1: ffff88807f6a94d0 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #1: ffff88807f6a94d0 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3634 #2: ffffffff8ed5c2a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #2: ffffffff8ed5c2a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8ed5c2a0 (rcu_read_lock){....}-{1:3}, at: netif_receive_skb_core+0x33/0x2b0 net/core/dev.c:6289 stack backtrace: CPU: 0 UID: 0 PID: 26903 Comm: syz.8.4888 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_usage_bug+0x28c/0x2e0 kernel/locking/lockdep.c:4086 valid_state+0xbe/0xf0 kernel/locking/lockdep.c:4100 mark_lock_irq+0x36/0x380 kernel/locking/lockdep.c:4311 mark_lock+0x117/0x190 kernel/locking/lockdep.c:4797 mark_usage kernel/locking/lockdep.c:-1 [inline] __lock_acquire+0x71e/0x2de0 kernel/locking/lockdep.c:5242 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 lock_sock_nested+0x41/0x100 net/core/sock.c:3837 lock_sock include/net/sock.h:1713 [inline] x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1775 x25_lapb_receive_frame+0x1b0/0xfb0 net/x25/x25_dev.c:138 __netif_receive_skb_one_core net/core/dev.c:6265 [inline] netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6290 lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100 __napi_poll+0xaa/0x330 net/core/dev.c:7798 napi_poll net/core/dev.c:7861 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:8018 handle_softirqs+0x223/0x840 kernel/softirq.c:645 __do_softirq kernel/softirq.c:679 [inline] invoke_softirq kernel/softirq.c:519 [inline] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758 irq_exit_rcu+0x9/0x30 kernel/softirq.c:775 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:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:220 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:229 Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 da 15 b6 f5 48 89 df e8 92 8d b6 f5 e8 8d 15 e3 f5 fb bf 01 00 00 00 92 8c a7 f5 65 48 8b 05 0a 80 a8 07 48 85 c0 74 07 5b e9 cf 49 RSP: 0000:ffffc90004d8e490 EFLAGS: 00000206 RAX: 0000000000025a3f RBX: ffff88807f6a95b0 RCX: 8000000000000001 RDX: 0000000000000006 RSI: ffffffff8e418b63 RDI: 0000000000000001 RBP: ffffc90004d8e5f0 R08: ffffffff907a33bf R09: 1ffffffff20f4677 R10: dffffc0000000000 R11: fffffbfff20f4678 R12: dffffc0000000000 R13: ffffc90004d8e540 R14: 0000000000000000 R15: 0000000000000001 spin_unlock_irq include/linux/spinlock.h:413 [inline] shmem_add_to_page_cache+0xa5e/0xd40 mm/shmem.c:1147 shmem_alloc_and_add_folio+0x854/0xf60 mm/shmem.c:2208 shmem_get_folio_gfp+0x594/0x1330 mm/shmem.c:2735 shmem_get_folio mm/shmem.c:2834 [inline] shmem_write_begin+0x16c/0x330 mm/shmem.c:3469 generic_perform_write+0x2d5/0x8e0 mm/filemap.c:4392 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3644 __kernel_write_iter+0x44a/0x8f0 fs/read_write.c:621 dump_write_iter fs/coredump.c:1354 [inline] dump_emit_page fs/coredump.c:1527 [inline] dump_user_range+0x715/0xca0 fs/coredump.c:1595 elf_core_dump+0x346a/0x3a70 fs/binfmt_elf.c:2106 coredump_write fs/coredump.c:1146 [inline] do_coredump+0x5e50/0x69c0 fs/coredump.c:1231 vfs_coredump+0xb41/0x10f0 fs/coredump.c:1306 get_signal+0x108f/0x12c0 kernel/signal.c:3097 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop kernel/entry/common.c:101 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline] irqentry_exit+0x2ba/0x910 kernel/entry/common.c:152 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7fa89dd9e161 Code: 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 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fa89e025fa0 RCX: 00007fa89dd9e159 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007fa89de3506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fa89e026038 R14: 00007fa89e025fa0 R15: 00007ffe505cd348 BUG: sleeping function called from invalid context at net/core/sock.c:3839 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 26903, name: syz.8.4888 preempt_count: 101, expected: 0 RCU nest depth: 1, expected: 0 INFO: lockdep is turned off. Preemption disabled at: [<0000000000000000>] 0x0 CPU: 0 UID: 0 PID: 26903 Comm: syz.8.4888 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 __might_resched+0x36a/0x4c0 kernel/sched/core.c:9113 lock_sock_nested+0x56/0x100 net/core/sock.c:3839 lock_sock include/net/sock.h:1713 [inline] x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1775 x25_lapb_receive_frame+0x1b0/0xfb0 net/x25/x25_dev.c:138 __netif_receive_skb_one_core net/core/dev.c:6265 [inline] netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6290 lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100 __napi_poll+0xaa/0x330 net/core/dev.c:7798 napi_poll net/core/dev.c:7861 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:8018 handle_softirqs+0x223/0x840 kernel/softirq.c:645 __do_softirq kernel/softirq.c:679 [inline] invoke_softirq kernel/softirq.c:519 [inline] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758 irq_exit_rcu+0x9/0x30 kernel/softirq.c:775 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:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:220 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:229 Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 da 15 b6 f5 48 89 df e8 92 8d b6 f5 e8 8d 15 e3 f5 fb bf 01 00 00 00 92 8c a7 f5 65 48 8b 05 0a 80 a8 07 48 85 c0 74 07 5b e9 cf 49 RSP: 0000:ffffc90004d8e490 EFLAGS: 00000206 RAX: 0000000000025a3f RBX: ffff88807f6a95b0 RCX: 8000000000000001 RDX: 0000000000000006 RSI: ffffffff8e418b63 RDI: 0000000000000001 RBP: ffffc90004d8e5f0 R08: ffffffff907a33bf R09: 1ffffffff20f4677 R10: dffffc0000000000 R11: fffffbfff20f4678 R12: dffffc0000000000 R13: ffffc90004d8e540 R14: 0000000000000000 R15: 0000000000000001 spin_unlock_irq include/linux/spinlock.h:413 [inline] shmem_add_to_page_cache+0xa5e/0xd40 mm/shmem.c:1147 shmem_alloc_and_add_folio+0x854/0xf60 mm/shmem.c:2208 shmem_get_folio_gfp+0x594/0x1330 mm/shmem.c:2735 shmem_get_folio mm/shmem.c:2834 [inline] shmem_write_begin+0x16c/0x330 mm/shmem.c:3469 generic_perform_write+0x2d5/0x8e0 mm/filemap.c:4392 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3644 __kernel_write_iter+0x44a/0x8f0 fs/read_write.c:621 dump_write_iter fs/coredump.c:1354 [inline] dump_emit_page fs/coredump.c:1527 [inline] dump_user_range+0x715/0xca0 fs/coredump.c:1595 elf_core_dump+0x346a/0x3a70 fs/binfmt_elf.c:2106 coredump_write fs/coredump.c:1146 [inline] do_coredump+0x5e50/0x69c0 fs/coredump.c:1231 vfs_coredump+0xb41/0x10f0 fs/coredump.c:1306 get_signal+0x108f/0x12c0 kernel/signal.c:3097 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop kernel/entry/common.c:101 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline] irqentry_exit+0x2ba/0x910 kernel/entry/common.c:152 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7fa89dd9e161 Code: 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 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fa89e025fa0 RCX: 00007fa89dd9e159 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007fa89de3506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fa89e026038 R14: 00007fa89e025fa0 R15: 00007ffe505cd348 ---------------- Code disassembly (best guess): 0: 90 nop 1: f3 0f 1e fa endbr64 5: 53 push %rbx 6: 48 89 fb mov %rdi,%rbx 9: 48 83 c7 18 add $0x18,%rdi d: 48 8b 74 24 08 mov 0x8(%rsp),%rsi 12: e8 da 15 b6 f5 call 0xf5b615f1 17: 48 89 df mov %rbx,%rdi 1a: e8 92 8d b6 f5 call 0xf5b68db1 1f: e8 8d 15 e3 f5 call 0xf5e315b1 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 92 8c a7 f5 call 0xf5a78cc1 <-- trapping instruction 2f: 65 48 8b 05 0a 80 a8 mov %gs:0x7a8800a(%rip),%rax # 0x7a88041 36: 07 37: 48 85 c0 test %rax,%rax 3a: 74 07 je 0x43 3c: 5b pop %rbx 3d: e9 .byte 0xe9 3e: cf iret 3f: 49 rex.WB