Oops: general protection fault, probably for non-canonical address 0xdffffc000000000a: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000050-0x0000000000000057] CPU: 0 UID: 0 PID: 5994 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:skb_dst_update_pmtu_no_confirm include/net/dst.h:565 [inline] RIP: 0010:tnl_update_pmtu+0x52b/0x1190 net/ipv4/ip_tunnel.c:533 Code: c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 0d 3a 2a f8 4c 8b 3b 49 83 c7 50 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ff e8 e7 39 2a f8 4d 8b 3f 4d 85 ff 8b 5c RSP: 0018:ffffc90004ef6f68 EFLAGS: 00010206 RAX: 000000000000000a RBX: ffffffff9a2dcec8 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffffffff9a2dcec0 RDI: 0000000000000000 RBP: ffffffff9a2dcec0 R08: ffffffff89db11f3 R09: ffffffff8e35a3a0 R10: ffffc90004ef6f20 R11: fffff520009dede6 R12: ffff888112583800 R13: ffff888112583858 R14: 1ffff110224b070b R15: 0000000000000050 FS: 000055557643a500(0000) GS:ffff88818e328000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30363fff CR3: 00000001744e0000 CR4: 00000000000006f0 Call Trace: ip_tunnel_xmit+0xd36/0x2430 net/ipv4/ip_tunnel.c:805 __gre_xmit net/ipv4/ip_gre.c:490 [inline] ipgre_xmit+0x8e6/0xc60 net/ipv4/ip_gre.c:694 __netdev_start_xmit include/linux/netdevice.h:5273 [inline] netdev_start_xmit include/linux/netdevice.h:5282 [inline] xmit_one net/core/dev.c:3853 [inline] dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3869 __dev_queue_xmit+0x14dd/0x32a0 net/core/dev.c:4819 dev_queue_xmit include/linux/netdevice.h:3381 [inline] __bpf_tx_skb+0x18e/0x260 net/core/filter.c:2153 ____bpf_clone_redirect net/core/filter.c:2487 [inline] bpf_clone_redirect+0x313/0x4b0 net/core/filter.c:2450 bpf_prog_885767c90d177146+0x62/0x6b bpf_dispatcher_nop_func include/linux/bpf.h:1402 [inline] __bpf_prog_run include/linux/filter.h:723 [inline] bpf_prog_run include/linux/filter.h:730 [inline] bpf_test_run+0x354/0x830 net/bpf/test_run.c:423 bpf_prog_test_run_skb+0xe02/0x1ea0 net/bpf/test_run.c:1164 bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4714 __sys_bpf+0x643/0x950 kernel/bpf/syscall.c:6236 __do_sys_bpf kernel/bpf/syscall.c:6331 [inline] __se_sys_bpf kernel/bpf/syscall.c:6329 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6329 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fad0c59acb9 Code: ff c3 66 2e 0f 1f 84 00 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 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe97cab158 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fad0c815fa0 RCX: 00007fad0c59acb9 RDX: 0000000000000028 RSI: 0000200000000080 RDI: 000000000000000a RBP: 00007fad0c608bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fad0c815fac R14: 00007fad0c815fa0 R15: 00007fad0c815fa0 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:skb_dst_update_pmtu_no_confirm include/net/dst.h:565 [inline] RIP: 0010:tnl_update_pmtu+0x52b/0x1190 net/ipv4/ip_tunnel.c:533 Code: c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 0d 3a 2a f8 4c 8b 3b 49 83 c7 50 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ff e8 e7 39 2a f8 4d 8b 3f 4d 85 ff 8b 5c RSP: 0018:ffffc90004ef6f68 EFLAGS: 00010206 RAX: 000000000000000a RBX: ffffffff9a2dcec8 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffffffff9a2dcec0 RDI: 0000000000000000 RBP: ffffffff9a2dcec0 R08: ffffffff89db11f3 R09: ffffffff8e35a3a0 R10: ffffc90004ef6f20 R11: fffff520009dede6 R12: ffff888112583800 R13: ffff888112583858 R14: 1ffff110224b070b R15: 0000000000000050 FS: 000055557643a500(0000) GS:ffff88818e328000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30363fff CR3: 00000001744e0000 CR4: 00000000000006f0 ---------------- Code disassembly (best guess): 0: c1 e8 03 shr $0x3,%eax 3: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) 8: 74 08 je 0x12 a: 48 89 df mov %rbx,%rdi d: e8 0d 3a 2a f8 call 0xf82a3a1f 12: 4c 8b 3b mov (%rbx),%r15 15: 49 83 c7 50 add $0x50,%r15 19: 4c 89 f8 mov %r15,%rax 1c: 48 c1 e8 03 shr $0x3,%rax 20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 27: fc ff df * 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction 2e: 74 08 je 0x38 30: 4c 89 ff mov %r15,%rdi 33: e8 e7 39 2a f8 call 0xf82a3a1f 38: 4d 8b 3f mov (%r15),%r15 3b: 4d 85 ff test %r15,%r15 3e: 8b .byte 0x8b 3f: 5c pop %rsp