Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 1 UID: 0 PID: 3336 Comm: kworker/u8:12 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: ipv6_addrconf addrconf_dad_work RIP: 0010:task_cpu include/linux/sched.h:2268 [inline] RIP: 0010:is_task_rq_idle kernel/sched/core.c:6169 [inline] RIP: 0010:cookie_equals kernel/sched/core.c:6174 [inline] RIP: 0010:pick_next_task kernel/sched/core.c:6355 [inline] RIP: 0010:__schedule+0x4030/0x5550 kernel/sched/core.c:7143 Code: 24 80 00 00 00 e8 80 97 f2 f6 48 8b 84 24 80 00 00 00 48 8b 18 4c 8d 7b 14 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 87 04 00 00 45 8b 3f 49 83 ff 08 0f 83 98 RSP: 0018:ffffc9000decee20 EFLAGS: 00010003 RAX: 0000000000000002 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000003 RSI: 0000000000000001 RDI: ffff8880b863c918 RBP: ffffc9000decf008 R08: ffffffff8fcf38f7 R09: 1ffffffff1f9e71e R10: dffffc0000000000 R11: fffffbfff1f9e71f R12: ffff8880b873c658 R13: ffff888125b6b000 R14: 1ffff110170e7922 R15: 0000000000000014 FS: 0000000000000000(0000) GS:ffff888125b6b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd18a39c492 CR3: 000000003775e000 CR4: 00000000003526f0 Call Trace: preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7552 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8c0 kernel/entry/common.c:167 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:679 RIP: 0010:lock_release+0x2d7/0x3c0 kernel/locking/lockdep.c:5895 Code: 2c 1a 11 00 00 00 00 eb b5 e8 f5 8b 9c 09 f7 c3 00 02 00 00 74 b9 65 48 8b 05 a5 e6 19 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 ca 53 a0 09 cc 48 8d 3d a2 34 31 RSP: 0018:ffffc9000decf130 EFLAGS: 00000286 RAX: 7b6020a164bd4100 RBX: 0000000000000206 RCX: 0000000000000046 RDX: 00000000d0a09f79 RSI: ffffffff8dbdec30 RDI: ffffffff8bcc4d80 RBP: ffff888032fe2c48 R08: ffffffff8b40616c R09: ffffffff8e3cb2a0 R10: 0000000000000000 R11: fffffbfff1f9e71f R12: 0000000000000009 R13: 0000000000000009 R14: ffff8880b8740480 R15: ffff888032fe1f00 rt_spin_unlock+0x29/0x200 kernel/locking/spinlock_rt.c:80 spin_unlock include/linux/spinlock_rt.h:109 [inline] alloc_from_pcs mm/slub.c:4818 [inline] slab_alloc_node mm/slub.c:4929 [inline] __do_kmalloc_node mm/slub.c:5356 [inline] __kmalloc_noprof+0x293/0x7e0 mm/slub.c:5382 _kmalloc_noprof include/linux/slab.h:973 [inline] _kzalloc_noprof include/linux/slab.h:1287 [inline] nsim_fib6_event_init drivers/net/netdevsim/fib.c:810 [inline] nsim_fib6_prepare_event drivers/net/netdevsim/fib.c:947 [inline] nsim_fib_event_schedule_work drivers/net/netdevsim/fib.c:1003 [inline] nsim_fib_event_nb+0x289/0x1240 drivers/net/netdevsim/fib.c:1043 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85 atomic_notifier_call_chain+0xda/0x180 kernel/notifier.c:223 call_fib_notifiers+0x31/0x60 net/core/fib_notifier.c:36 call_fib6_entry_notifiers net/ipv6/ip6_fib.c:412 [inline] fib6_add_rt2node+0x15ff/0x3940 net/ipv6/ip6_fib.c:1259 fib6_add+0x8e7/0x18c0 net/ipv6/ip6_fib.c:1535 __ip6_ins_rt net/ipv6/route.c:1355 [inline] ip6_ins_rt+0xed/0x160 net/ipv6/route.c:1365 __ipv6_ifa_notify+0x4e8/0xc60 net/ipv6/addrconf.c:6310 ipv6_ifa_notify net/ipv6/addrconf.c:6349 [inline] addrconf_dad_completed+0x1b5/0xe60 net/ipv6/addrconf.c:4347 addrconf_dad_work+0xdc4/0x1680 include/linux/rwlock_rt.h:-1 process_one_work+0x98b/0x1630 kernel/workqueue.c:3326 process_scheduled_works kernel/workqueue.c:3409 [inline] worker_thread+0xb49/0x1140 kernel/workqueue.c:3490 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:task_cpu include/linux/sched.h:2268 [inline] RIP: 0010:is_task_rq_idle kernel/sched/core.c:6169 [inline] RIP: 0010:cookie_equals kernel/sched/core.c:6174 [inline] RIP: 0010:pick_next_task kernel/sched/core.c:6355 [inline] RIP: 0010:__schedule+0x4030/0x5550 kernel/sched/core.c:7143 Code: 24 80 00 00 00 e8 80 97 f2 f6 48 8b 84 24 80 00 00 00 48 8b 18 4c 8d 7b 14 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 87 04 00 00 45 8b 3f 49 83 ff 08 0f 83 98 RSP: 0018:ffffc9000decee20 EFLAGS: 00010003 RAX: 0000000000000002 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000003 RSI: 0000000000000001 RDI: ffff8880b863c918 RBP: ffffc9000decf008 R08: ffffffff8fcf38f7 R09: 1ffffffff1f9e71e R10: dffffc0000000000 R11: fffffbfff1f9e71f R12: ffff8880b873c658 R13: ffff888125b6b000 R14: 1ffff110170e7922 R15: 0000000000000014 FS: 0000000000000000(0000) GS:ffff888125b6b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd18a39c492 CR3: 000000003775e000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: 24 80 and $0x80,%al 2: 00 00 add %al,(%rax) 4: 00 e8 add %ch,%al 6: 80 97 f2 f6 48 8b 84 adcb $0x84,-0x74b7090e(%rdi) d: 24 80 and $0x80,%al f: 00 00 add %al,(%rax) 11: 00 48 8b add %cl,-0x75(%rax) 14: 18 4c 8d 7b sbb %cl,0x7b(%rbp,%rcx,4) 18: 14 4c adc $0x4c,%al 1a: 89 f8 mov %edi,%eax 1c: 48 c1 e8 03 shr $0x3,%rax 20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 27: fc ff df * 2a: 0f b6 04 08 movzbl (%rax,%rcx,1),%eax <-- trapping instruction 2e: 84 c0 test %al,%al 30: 0f 85 87 04 00 00 jne 0x4bd 36: 45 8b 3f mov (%r15),%r15d 39: 49 83 ff 08 cmp $0x8,%r15 3d: 0f .byte 0xf 3e: 83 .byte 0x83 3f: 98 cwtl