================================ WARNING: inconsistent lock state syzkaller #0 Tainted: G L -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. syz.2.2808/19409 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff888026862260 (sk_lock-AF_X25){+.?.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] ffff888026862260 (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 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x73a/0x2360 kernel/exit.c:1008 do_group_exit+0x22d/0x2f0 kernel/exit.c:1151 get_signal+0x121b/0x12c0 kernel/signal.c:3039 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:336 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f irq event stamp: 22938 hardirqs last enabled at (22938): [] __local_bh_enable_ip+0xd6/0x140 kernel/softirq.c:478 hardirqs last disabled at (22937): [] __local_bh_enable_ip+0x72/0x140 kernel/softirq.c:455 softirqs last enabled at (19396): [] __do_softirq kernel/softirq.c:679 [inline] softirqs last enabled at (19396): [] invoke_softirq kernel/softirq.c:519 [inline] softirqs last enabled at (19396): [] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767 softirqs last disabled at (22893): [] __do_softirq kernel/softirq.c:679 [inline] softirqs last disabled at (22893): [] invoke_softirq kernel/softirq.c:519 [inline] softirqs last disabled at (22893): [] __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.2.2808/19409: 4, last CPU#0: #0: ffff88802c13c460 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1126 [inline] #0: ffff88802c13c460 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x3766/0x4530 fs/coredump.c:1195 #1: ffff888021ff9aa8 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1025 [inline] #1: ffff888021ff9aa8 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3429 #2: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #2: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: get_obj_cgroup_from_memcg mm/memcontrol.c:2987 [inline] #2: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: charge_memcg+0x47/0x310 mm/memcontrol.c:5202 #3: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #3: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: netif_receive_skb_core+0x33/0x2b0 net/core/dev.c:6269 stack backtrace: CPU: 0 UID: 0 PID: 19409 Comm: syz.2.2808 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: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+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:obj_cgroup_is_root include/linux/memcontrol.h:541 [inline] RIP: 0010:obj_cgroup_tryget include/linux/memcontrol.h:769 [inline] RIP: 0010:__get_obj_cgroup_from_memcg+0x8f/0x150 mm/memcontrol.c:2975 Code: 4d 8b 36 e8 b3 67 9c 09 85 c0 74 09 e8 ba ba 6b ff 85 c0 74 68 4d 85 f6 74 32 4d 8d 7e 30 4c 89 f8 48 c1 e8 03 42 0f b6 04 20 <84> c0 0f 85 81 00 00 00 41 80 3f 00 0f 85 95 00 00 00 4c 89 f7 e8 RSP: 0000:ffffc90004ae66e8 EFLAGS: 00000a06 RAX: 0000000000000000 RBX: ffff888079adc4c0 RCX: 0000000000000046 RDX: 00000000d212f587 RSI: ffffffff8e4dc9a1 RDI: ffffffff8c4c9480 RBP: 0000000000000818 R08: 4c00000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb5c8a0 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff88807e3f9f80 R15: ffff88807e3f9fb0 get_obj_cgroup_from_memcg mm/memcontrol.c:2988 [inline] charge_memcg+0xb6/0x310 mm/memcontrol.c:5202 __mem_cgroup_charge+0x25/0x80 mm/memcontrol.c:5222 mem_cgroup_charge include/linux/memcontrol.h:657 [inline] shmem_alloc_and_add_folio+0x7bb/0xf60 mm/shmem.c:1984 shmem_get_folio_gfp+0x5da/0x16d0 mm/shmem.c:2527 shmem_get_folio mm/shmem.c:2633 [inline] shmem_write_begin+0x16c/0x330 mm/shmem.c:3264 generic_perform_write+0x2d5/0x8f0 mm/filemap.c:4374 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3439 __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: 0033:0x7fcf82b9e0e1 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: 00007fcf82e26090 RCX: 00007fcf82b9e0d9 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007fcf82c35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fcf82e26128 R14: 00007fcf82e26090 R15: 00007ffdc842f878 BUG: sleeping function called from invalid context at net/core/sock.c:3829 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 19409, name: syz.2.2808 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: 0 UID: 0 PID: 19409 Comm: syz.2.2808 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:9203 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+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:obj_cgroup_is_root include/linux/memcontrol.h:541 [inline] RIP: 0010:obj_cgroup_tryget include/linux/memcontrol.h:769 [inline] RIP: 0010:__get_obj_cgroup_from_memcg+0x8f/0x150 mm/memcontrol.c:2975 Code: 4d 8b 36 e8 b3 67 9c 09 85 c0 74 09 e8 ba ba 6b ff 85 c0 74 68 4d 85 f6 74 32 4d 8d 7e 30 4c 89 f8 48 c1 e8 03 42 0f b6 04 20 <84> c0 0f 85 81 00 00 00 41 80 3f 00 0f 85 95 00 00 00 4c 89 f7 e8 RSP: 0000:ffffc90004ae66e8 EFLAGS: 00000a06 RAX: 0000000000000000 RBX: ffff888079adc4c0 RCX: 0000000000000046 RDX: 00000000d212f587 RSI: ffffffff8e4dc9a1 RDI: ffffffff8c4c9480 RBP: 0000000000000818 R08: 4c00000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb5c8a0 R12: dffffc0000000000 R13: 0000000000000000 R14: ffff88807e3f9f80 R15: ffff88807e3f9fb0 get_obj_cgroup_from_memcg mm/memcontrol.c:2988 [inline] charge_memcg+0xb6/0x310 mm/memcontrol.c:5202 __mem_cgroup_charge+0x25/0x80 mm/memcontrol.c:5222 mem_cgroup_charge include/linux/memcontrol.h:657 [inline] shmem_alloc_and_add_folio+0x7bb/0xf60 mm/shmem.c:1984 shmem_get_folio_gfp+0x5da/0x16d0 mm/shmem.c:2527 shmem_get_folio mm/shmem.c:2633 [inline] shmem_write_begin+0x16c/0x330 mm/shmem.c:3264 generic_perform_write+0x2d5/0x8f0 mm/filemap.c:4374 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3439 __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: 0033:0x7fcf82b9e0e1 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: 00007fcf82e26090 RCX: 00007fcf82b9e0d9 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007fcf82c35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fcf82e26128 R14: 00007fcf82e26090 R15: 00007ffdc842f878 EXT4-fs (loop5): error count since last fsck: 1 EXT4-fs (loop5): initial error at time 1786591080: ext4_get_branch:178: inode 13: block 1024 EXT4-fs (loop5): last error at time 1786591080: ext4_get_branch:178: inode 13: block 1024 ---------------- Code disassembly (best guess): 0: 4d 8b 36 mov (%r14),%r14 3: e8 b3 67 9c 09 call 0x99c67bb 8: 85 c0 test %eax,%eax a: 74 09 je 0x15 c: e8 ba ba 6b ff call 0xff6bbacb 11: 85 c0 test %eax,%eax 13: 74 68 je 0x7d 15: 4d 85 f6 test %r14,%r14 18: 74 32 je 0x4c 1a: 4d 8d 7e 30 lea 0x30(%r14),%r15 1e: 4c 89 f8 mov %r15,%rax 21: 48 c1 e8 03 shr $0x3,%rax 25: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax * 2a: 84 c0 test %al,%al <-- trapping instruction 2c: 0f 85 81 00 00 00 jne 0xb3 32: 41 80 3f 00 cmpb $0x0,(%r15) 36: 0f 85 95 00 00 00 jne 0xd1 3c: 4c 89 f7 mov %r14,%rdi 3f: e8 .byte 0xe8