Oops: general protection fault, probably for non-canonical address 0xdffffc000000000e: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000070-0x0000000000000077] CPU: 3 UID: 0 PID: 16798 Comm: syz.8.3088 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:skb_segment+0x189c/0x3e20 net/core/skbuff.c:4803 Code: 00 00 fe e9 9b eb ff ff e8 21 0e 52 f8 48 8b 84 24 c8 00 00 00 48 8d 78 70 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 09 3c 03 7f 05 e8 93 64 b8 f8 48 8b 84 24 c8 RSP: 0018:ffffc90004eee890 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000020048 RCX: ffffc90006669000 RDX: 000000000000000e RSI: ffffffff8969831f RDI: 0000000000000070 RBP: ffffc90004eee9d8 R08: 0000000000000005 R09: 000000000000ffff R10: 000000000000ffff R11: aaaa0aaaaaaaaaaa R12: ffff888060b5e540 R13: 000000000001fffe R14: 000000000001fffe R15: 000000000000ffff FS: 00007f2220a366c0(0000) GS:ffff8880d69bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000200000 CR3: 0000000040fbc000 CR4: 0000000000352ef0 Call Trace: tcp_gso_segment+0x3be/0x19e0 net/ipv4/tcp_offload.c:180 tcp6_gso_segment net/ipv6/tcpv6_offload.c:193 [inline] tcp6_gso_segment+0x1ec/0x1140 net/ipv6/tcpv6_offload.c:160 ipv6_gso_segment+0x7f2/0x1d60 net/ipv6/ip6_offload.c:154 skb_mac_gso_segment+0x2a8/0x650 net/core/gso.c:53 __skb_gso_segment+0x36e/0x700 net/core/gso.c:124 skb_gso_segment include/net/gso.h:83 [inline] validate_xmit_skb+0x662/0x1200 net/core/dev.c:3947 validate_xmit_skb_list+0xc1/0x130 net/core/dev.c:3997 sch_direct_xmit+0x433/0xcf0 net/sched/sch_generic.c:329 qdisc_restart net/sched/sch_generic.c:409 [inline] __qdisc_run+0x541/0x1bf0 net/sched/sch_generic.c:417 __dev_xmit_skb net/core/dev.c:4171 [inline] __dev_queue_xmit+0x2b43/0x4490 net/core/dev.c:4679 dev_queue_xmit include/linux/netdevice.h:3361 [inline] neigh_hh_output include/net/neighbour.h:531 [inline] neigh_output include/net/neighbour.h:545 [inline] ip6_finish_output2+0xe98/0x2020 net/ipv6/ip6_output.c:141 __ip6_finish_output+0x3cd/0x1010 net/ipv6/ip6_output.c:215 ip6_finish_output net/ipv6/ip6_output.c:226 [inline] NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x1ca/0x3e0 net/ipv6/ip6_output.c:248 dst_output include/net/dst.h:461 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ip6_xmit+0x12d6/0x22f0 net/ipv6/ip6_output.c:367 inet6_csk_xmit+0x3c7/0x740 net/ipv6/inet6_connection_sock.c:120 __tcp_transmit_skb+0x19bb/0x3df0 net/ipv4/tcp_output.c:1479 tcp_transmit_skb net/ipv4/tcp_output.c:1497 [inline] tcp_write_xmit+0x1274/0x84e0 net/ipv4/tcp_output.c:2833 __tcp_push_pending_frames+0xaf/0x390 net/ipv4/tcp_output.c:3016 tcp_push_pending_frames include/net/tcp.h:2173 [inline] tcp_data_snd_check net/ipv4/tcp_input.c:5666 [inline] tcp_rcv_established+0x90e/0x23f0 net/ipv4/tcp_input.c:6218 tcp_v6_do_rcv+0x895/0x1740 net/ipv6/tcp_ipv6.c:1649 sk_backlog_rcv include/net/sock.h:1148 [inline] __release_sock+0x14c/0x400 net/core/sock.c:3194 __sk_flush_backlog+0x27/0xc0 net/core/sock.c:3214 sk_flush_backlog include/net/sock.h:1211 [inline] tcp_sendmsg_locked+0x3957/0x42a0 net/ipv4/tcp.c:1194 tcp_sendmsg+0x2e/0x50 net/ipv4/tcp.c:1393 inet6_sendmsg+0xb9/0x140 net/ipv6/af_inet6.c:659 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg net/socket.c:729 [inline] __sys_sendto+0x376/0x520 net/socket.c:2228 __do_sys_sendto net/socket.c:2235 [inline] __se_sys_sendto net/socket.c:2231 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2231 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f221fb8ebe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2220a36038 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f221fdb5fa0 RCX: 00007f221fb8ebe9 RDX: ffffffffffffff1d RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007f221fc11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000850 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f221fdb6038 R14: 00007f221fdb5fa0 R15: 00007fff3757d4e8 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:skb_segment+0x189c/0x3e20 net/core/skbuff.c:4803 Code: 00 00 fe e9 9b eb ff ff e8 21 0e 52 f8 48 8b 84 24 c8 00 00 00 48 8d 78 70 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 09 3c 03 7f 05 e8 93 64 b8 f8 48 8b 84 24 c8 RSP: 0018:ffffc90004eee890 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000020048 RCX: ffffc90006669000 RDX: 000000000000000e RSI: ffffffff8969831f RDI: 0000000000000070 RBP: ffffc90004eee9d8 R08: 0000000000000005 R09: 000000000000ffff R10: 000000000000ffff R11: aaaa0aaaaaaaaaaa R12: ffff888060b5e540 R13: 000000000001fffe R14: 000000000001fffe R15: 000000000000ffff FS: 00007f2220a366c0(0000) GS:ffff8880d69bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000200000 CR3: 0000000040fbc000 CR4: 0000000000352ef0 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 00 fe add %bh,%dh 2: e9 9b eb ff ff jmp 0xffffeba2 7: e8 21 0e 52 f8 call 0xf8520e2d c: 48 8b 84 24 c8 00 00 mov 0xc8(%rsp),%rax 13: 00 14: 48 8d 78 70 lea 0x70(%rax),%rdi 18: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1f: fc ff df 22: 48 89 fa mov %rdi,%rdx 25: 48 c1 ea 03 shr $0x3,%rdx * 29: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction 2d: 84 c0 test %al,%al 2f: 74 09 je 0x3a 31: 3c 03 cmp $0x3,%al 33: 7f 05 jg 0x3a 35: e8 93 64 b8 f8 call 0xf8b864cd 3a: 48 rex.W 3b: 8b .byte 0x8b 3c: 84 24 c8 test %ah,(%rax,%rcx,8)