syzbot

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BUG: KMSAN: uninit-value in pskb_may_pull include/linux/skbuff.h:2114 [inline]
BUG: KMSAN: uninit-value in ipv6_gso_pull_exthdrs net/ipv6/ip6_offload.c:47 [inline]
BUG: KMSAN: uninit-value in ipv6_gso_segment+0x925/0x1f00 net/ipv6/ip6_offload.c:87
CPU: 1 PID: 8419 Comm: syz-executor2 Not tainted 4.18.0-rc4+ #27
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x185/0x1e0 lib/dump_stack.c:113
 kmsan_report+0x195/0x2c0 mm/kmsan/kmsan.c:982
 __msan_warning+0x7d/0xe0 mm/kmsan/kmsan_instr.c:645
 pskb_may_pull include/linux/skbuff.h:2114 [inline]
 ipv6_gso_pull_exthdrs net/ipv6/ip6_offload.c:47 [inline]
 ipv6_gso_segment+0x925/0x1f00 net/ipv6/ip6_offload.c:87
 skb_mac_gso_segment+0x456/0x7e0 net/core/dev.c:2792
 nsh_gso_segment+0x658/0x1340 net/nsh/nsh.c:111
 skb_mac_gso_segment+0x456/0x7e0 net/core/dev.c:2792
 __skb_gso_segment+0x757/0xa40 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4099 [inline]
 validate_xmit_skb+0xc30/0x1320 net/core/dev.c:3104
 __dev_queue_xmit+0x2443/0x3c70 net/core/dev.c:3561
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3602
 packet_snd net/packet/af_packet.c:2919 [inline]
 packet_sendmsg+0x8469/0x9010 net/packet/af_packet.c:2944
 sock_sendmsg_nosec net/socket.c:641 [inline]
 sock_sendmsg net/socket.c:651 [inline]
 __sys_sendto+0x798/0x8e0 net/socket.c:1797
 __do_sys_sendto net/socket.c:1809 [inline]
 __se_sys_sendto net/socket.c:1805 [inline]
 __x64_sys_sendto+0x1a1/0x210 net/socket.c:1805
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x455ab9
Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007fcd37b12c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fcd37b136d4 RCX: 0000000000455ab9
RDX: 0000000000000012 RSI: 0000000020000000 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 00000000200000c0 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004c1164 R14: 00000000004d1860 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:256 [inline]
 kmsan_internal_alloc_meta_for_pages+0x157/0x730 mm/kmsan/kmsan.c:694
 kmsan_alloc_page+0x80/0xe0 mm/kmsan/kmsan_hooks.c:250
 __alloc_pages_nodemask+0x105b/0x6320 mm/page_alloc.c:4409
 alloc_pages_current+0x6b1/0x970 mm/mempolicy.c:2093
 alloc_pages include/linux/gfp.h:494 [inline]
 alloc_slab_page mm/slub.c:1452 [inline]
 allocate_slab mm/slub.c:1597 [inline]
 new_slab+0x353/0x1bc0 mm/slub.c:1668
 new_slab_objects mm/slub.c:2431 [inline]
 ___slab_alloc+0x1623/0x2090 mm/slub.c:2583
 __slab_alloc mm/slub.c:2623 [inline]
 slab_alloc_node mm/slub.c:2686 [inline]
 slab_alloc mm/slub.c:2728 [inline]
 kmem_cache_alloc+0x666/0xbb0 mm/slub.c:2733
 sk_prot_alloc+0xf6/0x4b0 net/core/sock.c:1475
 sk_alloc+0xf1/0xc00 net/core/sock.c:1535
 inet6_create+0x75f/0x16f0 net/ipv6/af_inet6.c:183
 __sock_create+0x723/0xf70 net/socket.c:1286
 sock_create net/socket.c:1326 [inline]
 __sys_socket+0x184/0x670 net/socket.c:1356
 __do_sys_socket net/socket.c:1365 [inline]
 __se_sys_socket net/socket.c:1363 [inline]
 __x64_sys_socket+0xd8/0x120 net/socket.c:1363
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
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