================================ WARNING: inconsistent lock state syzkaller #0 Tainted: G L -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. syz.7.588/9357 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff888034a94260 (sk_lock-AF_X25){+.?.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] ffff888034a94260 (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:513 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+0x204/0x770 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:336 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f irq event stamp: 203790 hardirqs last enabled at (203790): [] __local_bh_enable_ip+0xd6/0x140 kernel/softirq.c:478 hardirqs last disabled at (203789): [] __local_bh_enable_ip+0x72/0x140 kernel/softirq.c:455 softirqs last enabled at (199710): [] __do_softirq kernel/softirq.c:679 [inline] softirqs last enabled at (199710): [] invoke_softirq kernel/softirq.c:519 [inline] softirqs last enabled at (199710): [] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767 softirqs last disabled at (203685): [] __do_softirq kernel/softirq.c:679 [inline] softirqs last disabled at (203685): [] invoke_softirq kernel/softirq.c:519 [inline] softirqs last disabled at (203685): [] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767 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.7.588/9357: 3, last CPU#1: #0: ffff88807abfa460 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1126 [inline] #0: ffff88807abfa460 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x3766/0x4530 fs/coredump.c:1195 #1: ffff888028aeacc0 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #1: ffff888028aeacc0 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3430 #2: ffffffff8ed5c720 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #2: ffffffff8ed5c720 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8ed5c720 (rcu_read_lock){....}-{1:3}, at: netif_receive_skb_core+0x33/0x2b0 net/core/dev.c:6288 stack backtrace: CPU: 1 UID: 0 PID: 9357 Comm: syz.7.588 Tainted: G L syzkaller #0 PREEMPT(full) 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+0x28c/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:6264 [inline] netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6289 lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100 __napi_poll+0xaa/0x330 net/core/dev.c:7787 napi_poll net/core/dev.c:7850 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:8007 handle_softirqs+0x226/0x860 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:767 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784 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:lock_release+0x2e1/0x3c0 kernel/locking/lockdep.c:5934 Code: b1 f1 11 00 00 00 00 eb b5 e8 0b 51 41 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 63 6c f1 11 48 3b 44 24 28 75 48 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 c0 54 44 0a cc 48 8d 3d 58 40 da RSP: 0018:ffffc900035f5fc8 EFLAGS: 00000282 RAX: e9ad71bfd0d6ad00 RBX: 0000000000000206 RCX: 0000000000000046 RDX: ffffc900035f6001 RSI: ffffffff8e700a53 RDI: ffffffff8c6d9380 RBP: ffff8880381469c0 R08: ffffc900035f66e8 R09: 0000000000000000 R10: ffffc900035f60f8 R11: fffff520006bec21 R12: 0000000000000002 R13: 0000000000000002 R14: ffffffff8ed5c720 R15: ffff888038145dc0 rcu_lock_release include/linux/rcupdate.h:319 [inline] rcu_read_unlock include/linux/rcupdate.h:880 [inline] class_rcu_destructor include/linux/rcupdate.h:1216 [inline] unwind_next_frame+0x1baa/0x2550 arch/x86/kernel/unwind_orc.c:709 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:183 __set_page_owner+0x8d/0x4c0 mm/page_owner.c:359 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436 alloc_pages_mpol+0x21e/0x390 mm/mempolicy.c:2486 folio_alloc_mpol_noprof+0x39/0x160 mm/mempolicy.c:2505 shmem_alloc_folio mm/shmem.c:1933 [inline] shmem_alloc_and_add_folio+0x43e/0xf60 mm/shmem.c:1975 shmem_get_folio_gfp+0x5da/0x16d0 mm/shmem.c:2528 shmem_get_folio mm/shmem.c:2634 [inline] shmem_write_begin+0x16c/0x330 mm/shmem.c:3265 generic_perform_write+0x2d5/0x8f0 mm/filemap.c:4374 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3440 __kernel_write_iter+0x44a/0x8f0 fs/read_write.c:621 dump_emit_page fs/coredump.c:1293 [inline] dump_user_range+0xc19/0x12c0 fs/coredump.c:1367 elf_core_dump+0x3485/0x3a90 fs/binfmt_elf.c:2106 coredump_write+0x1290/0x1960 fs/coredump.c:1047 do_coredump fs/coredump.c:1126 [inline] vfs_coredump+0x3766/0x4530 fs/coredump.c:1195 get_signal+0x1094/0x12c0 kernel/signal.c:3024 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:165 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7f745359e161 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: 00007f7453826090 RCX: 00007f745359e159 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007f7453635024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f7453826128 R14: 00007f7453826090 R15: 00007ffc2acdcee8 BUG: sleeping function called from invalid context at net/core/sock.c:3829 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 9357, name: syz.7.588 preempt_count: 100, expected: 0 RCU nest depth: 2, expected: 0 INFO: lockdep is turned off. Preemption disabled at: [] softirq_handle_begin kernel/softirq.c:486 [inline] [] handle_softirqs+0xab/0x860 kernel/softirq.c:621 CPU: 1 UID: 0 PID: 9357 Comm: syz.7.588 Tainted: G L syzkaller #0 PREEMPT(full) 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+0x36a/0x4c0 kernel/sched/core.c:9234 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:6264 [inline] netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6289 lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100 __napi_poll+0xaa/0x330 net/core/dev.c:7787 napi_poll net/core/dev.c:7850 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:8007 handle_softirqs+0x226/0x860 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:767 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784 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:lock_release+0x2e1/0x3c0 kernel/locking/lockdep.c:5934 Code: b1 f1 11 00 00 00 00 eb b5 e8 0b 51 41 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 63 6c f1 11 48 3b 44 24 28 75 48 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 c0 54 44 0a cc 48 8d 3d 58 40 da RSP: 0018:ffffc900035f5fc8 EFLAGS: 00000282 RAX: e9ad71bfd0d6ad00 RBX: 0000000000000206 RCX: 0000000000000046 RDX: ffffc900035f6001 RSI: ffffffff8e700a53 RDI: ffffffff8c6d9380 RBP: ffff8880381469c0 R08: ffffc900035f66e8 R09: 0000000000000000 R10: ffffc900035f60f8 R11: fffff520006bec21 R12: 0000000000000002 R13: 0000000000000002 R14: ffffffff8ed5c720 R15: ffff888038145dc0 rcu_lock_release include/linux/rcupdate.h:319 [inline] rcu_read_unlock include/linux/rcupdate.h:880 [inline] class_rcu_destructor include/linux/rcupdate.h:1216 [inline] unwind_next_frame+0x1baa/0x2550 arch/x86/kernel/unwind_orc.c:709 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:183 __set_page_owner+0x8d/0x4c0 mm/page_owner.c:359 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436 alloc_pages_mpol+0x21e/0x390 mm/mempolicy.c:2486 folio_alloc_mpol_noprof+0x39/0x160 mm/mempolicy.c:2505 shmem_alloc_folio mm/shmem.c:1933 [inline] shmem_alloc_and_add_folio+0x43e/0xf60 mm/shmem.c:1975 shmem_get_folio_gfp+0x5da/0x16d0 mm/shmem.c:2528 shmem_get_folio mm/shmem.c:2634 [inline] shmem_write_begin+0x16c/0x330 mm/shmem.c:3265 generic_perform_write+0x2d5/0x8f0 mm/filemap.c:4374 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3440 __kernel_write_iter+0x44a/0x8f0 fs/read_write.c:621 dump_emit_page fs/coredump.c:1293 [inline] dump_user_range+0xc19/0x12c0 fs/coredump.c:1367 elf_core_dump+0x3485/0x3a90 fs/binfmt_elf.c:2106 coredump_write+0x1290/0x1960 fs/coredump.c:1047 do_coredump fs/coredump.c:1126 [inline] vfs_coredump+0x3766/0x4530 fs/coredump.c:1195 get_signal+0x1094/0x12c0 kernel/signal.c:3024 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:165 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7f745359e161 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: 00007f7453826090 RCX: 00007f745359e159 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007f7453635024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f7453826128 R14: 00007f7453826090 R15: 00007ffc2acdcee8 ---------------- Code disassembly (best guess): 0: b1 f1 mov $0xf1,%cl 2: 11 00 adc %eax,(%rax) 4: 00 00 add %al,(%rax) 6: 00 eb add %ch,%bl 8: b5 e8 mov $0xe8,%ch a: 0b 51 41 or 0x41(%rcx),%edx d: 0a f7 or %bh,%dh f: c3 ret 10: 00 02 add %al,(%rdx) 12: 00 00 add %al,(%rax) 14: 74 b9 je 0xffffffcf 16: 65 48 8b 05 63 6c f1 mov %gs:0x11f16c63(%rip),%rax # 0x11f16c81 1d: 11 1e: 48 3b 44 24 28 cmp 0x28(%rsp),%rax 23: 75 48 jne 0x6d 25: fb sti 26: 48 83 c4 30 add $0x30,%rsp * 2a: 5b pop %rbx <-- trapping instruction 2b: 41 5c pop %r12 2d: 41 5d pop %r13 2f: 41 5e pop %r14 31: 41 5f pop %r15 33: 5d pop %rbp 34: e9 c0 54 44 0a jmp 0xa4454f9 39: cc int3 3a: 48 rex.W 3b: 8d .byte 0x8d 3c: 3d .byte 0x3d 3d: 58 pop %rax 3e: 40 rex 3f: da .byte 0xda