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: 12 Comm: kworker/u8:0 Not tainted 6.16.0-syzkaller-06620-gae633388cae3-dirty #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Workqueue: ipv6_addrconf addrconf_dad_work RIP: 0010:__ptr_ring_full include/linux/ptr_ring.h:51 [inline] RIP: 0010:ptr_ring_full include/linux/ptr_ring.h:59 [inline] RIP: 0010:tun_net_xmit+0x3ee/0x19c0 drivers/net/tun.c:1026 Code: 54 24 18 48 89 d0 48 c1 e8 03 48 89 44 24 58 42 0f b6 04 28 84 c0 0f 85 f9 11 00 00 48 63 02 48 8d 1c c3 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 d3 0f ac fb 48 8b 1b 48 8b 7c 24 RSP: 0018:ffffc900000f6f00 EFLAGS: 00010202 RAX: 0000000000000002 RBX: 0000000000000010 RCX: dffffc0000000000 RDX: ffff88811bf90940 RSI: 0000000000000004 RDI: ffffc900000f6e80 RBP: ffffc900000f7050 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200001edd0 R12: 0000000000000000 R13: dffffc0000000000 R14: ffff8881054c8000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881a3c80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000002280 CR3: 0000000110b70000 CR4: 00000000000006f0 Call Trace: __netdev_start_xmit include/linux/netdevice.h:5219 [inline] netdev_start_xmit include/linux/netdevice.h:5228 [inline] xmit_one net/core/dev.c:3827 [inline] dev_hard_start_xmit+0x2d7/0x830 net/core/dev.c:3843 sch_direct_xmit+0x241/0x4b0 net/sched/sch_generic.c:344 __dev_xmit_skb net/core/dev.c:4102 [inline] __dev_queue_xmit+0x1857/0x3b50 net/core/dev.c:4679 neigh_output include/net/neighbour.h:547 [inline] ip6_finish_output2+0x11fe/0x16a0 net/ipv6/ip6_output.c:141 NF_HOOK include/linux/netfilter.h:318 [inline] ndisc_send_skb+0xb54/0x1440 net/ipv6/ndisc.c:512 addrconf_dad_completed+0x7ae/0xd60 net/ipv6/addrconf.c:4360 addrconf_dad_work+0xc36/0x14b0 net/ipv6/addrconf.c:-1 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__ptr_ring_full include/linux/ptr_ring.h:51 [inline] RIP: 0010:ptr_ring_full include/linux/ptr_ring.h:59 [inline] RIP: 0010:tun_net_xmit+0x3ee/0x19c0 drivers/net/tun.c:1026 Code: 54 24 18 48 89 d0 48 c1 e8 03 48 89 44 24 58 42 0f b6 04 28 84 c0 0f 85 f9 11 00 00 48 63 02 48 8d 1c c3 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 d3 0f ac fb 48 8b 1b 48 8b 7c 24 RSP: 0018:ffffc900000f6f00 EFLAGS: 00010202 RAX: 0000000000000002 RBX: 0000000000000010 RCX: dffffc0000000000 RDX: ffff88811bf90940 RSI: 0000000000000004 RDI: ffffc900000f6e80 RBP: ffffc900000f7050 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200001edd0 R12: 0000000000000000 R13: dffffc0000000000 R14: ffff8881054c8000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881a3c80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000002280 CR3: 0000000110b70000 CR4: 00000000000006f0 ---------------- Code disassembly (best guess): 0: 54 push %rsp 1: 24 18 and $0x18,%al 3: 48 89 d0 mov %rdx,%rax 6: 48 c1 e8 03 shr $0x3,%rax a: 48 89 44 24 58 mov %rax,0x58(%rsp) f: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax 14: 84 c0 test %al,%al 16: 0f 85 f9 11 00 00 jne 0x1215 1c: 48 63 02 movslq (%rdx),%rax 1f: 48 8d 1c c3 lea (%rbx,%rax,8),%rbx 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 48 89 df mov %rbx,%rdi 34: e8 d3 0f ac fb call 0xfbac100c 39: 48 8b 1b mov (%rbx),%rbx 3c: 48 rex.W 3d: 8b .byte 0x8b 3e: 7c 24 jl 0x64