------------[ cut here ]------------
len > ((int)(~0U >> 1))
WARNING: ./include/linux/skbuff.h:2864 at pskb_may_pull_reason include/linux/skbuff.h:2864 [inline], CPU#1: syz.0.2313/14784
WARNING: ./include/linux/skbuff.h:2864 at pskb_network_may_pull_reason include/linux/skbuff.h:3265 [inline], CPU#1: syz.0.2313/14784
WARNING: ./include/linux/skbuff.h:2864 at pskb_inet_may_pull_reason include/net/ip_tunnels.h:481 [inline], CPU#1: syz.0.2313/14784
WARNING: ./include/linux/skbuff.h:2864 at pskb_inet_may_pull include/net/ip_tunnels.h:486 [inline], CPU#1: syz.0.2313/14784
WARNING: ./include/linux/skbuff.h:2864 at ip6gre_tunnel_xmit+0xc78/0xf50 net/ipv6/ip6_gre.c:885, CPU#1: syz.0.2313/14784
Modules linked in:
CPU: 1 UID: 0 PID: 14784 Comm: syz.0.2313 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:pskb_may_pull_reason include/linux/skbuff.h:2864 [inline]
RIP: 0010:pskb_network_may_pull_reason include/linux/skbuff.h:3265 [inline]
RIP: 0010:pskb_inet_may_pull_reason include/net/ip_tunnels.h:481 [inline]
RIP: 0010:pskb_inet_may_pull include/net/ip_tunnels.h:486 [inline]
RIP: 0010:ip6gre_tunnel_xmit+0xc78/0xf50 net/ipv6/ip6_gre.c:885
Code: 8c 24 90 01 00 00 4c 89 ef be 02 00 00 00 31 d2 e8 2d 5c 01 00 e9 1f fe ff ff e8 c3 cf 2c f7 e9 15 fe ff ff e8 b9 cf 2c f7 90 <0f> 0b 90 e9 49 f5 ff ff 44 89 ff 44 89 ee e8 65 d1 2c f7 45 39 ef
RSP: 0018:ffffc9001bcdf420 EFLAGS: 00010287
RAX: ffffffff8a9a31a7 RBX: 1ffff9200379be90 RCX: 0000000000080000
RDX: ffffc9000614a000 RSI: 00000000000000d0 RDI: 00000000000000d1
RBP: ffffc9001bcdf6b0 R08: ffff88807f8cbe00 R09: 0000000000000002
R10: 0000000000004888 R11: ffffffff8a9a2530 R12: 0000000000000000
R13: ffff888026966500 R14: ffff8880269665d8 R15: 00000000ffffffc0
FS:  00007f968a3eb6c0(0000) GS:ffff88812504c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c35d530 CR3: 000000002bea6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __netdev_start_xmit include/linux/netdevice.h:5424 [inline]
 netdev_start_xmit include/linux/netdevice.h:5433 [inline]
 __dev_direct_xmit+0x4b6/0x730 net/core/dev.c:4967
 __xsk_generic_xmit net/xdp/xsk.c:1256 [inline]
 xsk_generic_xmit+0x272b/0x4730 net/xdp/xsk.c:1312
 __xsk_sendmsg net/xdp/xsk.c:1366 [inline]
 xsk_sendmsg+0x482/0x810 net/xdp/xsk.c:1376
 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775
 __sock_sendmsg net/socket.c:790 [inline]
 ____sys_sendmsg+0x54e/0x850 net/socket.c:2684
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
 __sys_sendmsg net/socket.c:2770 [inline]
 __do_sys_sendmsg net/socket.c:2775 [inline]
 __se_sys_sendmsg net/socket.c:2773 [inline]
 __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f968959e0d9
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:00007f968a3eb028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f9689825fa0 RCX: 00007f968959e0d9
RDX: 0000000000000040 RSI: 0000200000000700 RDI: 0000000000000005
RBP: 00007f9689635024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9689826038 R14: 00007f9689825fa0 R15: 00007ffe3ba15ae8
 </TASK>