BUG: unable to handle page fault for address: ffff888240000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 7801067 P4D 7801067 PUD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 29810 Comm: syz-executor.0 Not tainted 5.4.123-syzkaller-00835-g3e256ddba1ff #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:do_csum arch/x86/lib/csum-partial_64.c:72 [inline]
RIP: 0010:csum_partial+0x194/0x470 arch/x86/lib/csum-partial_64.c:136
Code: 89 44 24 28 45 31 ff 48 8b 6c 24 08 66 2e 0f 1f 84 00 00 00 00 00 4c 03 6d 00 4c 13 6d 08 4c 13 6d 10 4c 13 6d 18 4c 13 6d 20 <4c> 13 6d 28 4c 13 6d 30 4c 13 6d 38 4d 11 fd 45 85 f6 74 0e 48 83
RSP: 0018:ffff8881c1767408 EFLAGS: 00010212
RAX: ffffffff84446971 RBX: 000000001ffffffd RCX: 0000000000040000
RDX: ffffc90008ca2000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffff88823fffffd8 R08: ffffffff84446911 R09: 0000000000000000
R10: ffffed103c04605d R11: 0000000000000000 R12: 00000000ffffffec
R13: 77968a9230221725 R14: 0000000002808c01 R15: 0000000000000000
FS:  00007f5b61e97700(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff888240000000 CR3: 00000001b008d000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 lco_csum include/linux/skbuff.h:4543 [inline]
 gre_checksum include/net/gre.h:114 [inline]
 gre_build_header+0x477/0x780 include/net/gre.h:149
 __gre_xmit net/ipv4/ip_gre.c:440 [inline]
 ipgre_xmit+0x6ab/0x9e0 net/ipv4/ip_gre.c:626
 __netdev_start_xmit include/linux/netdevice.h:4506 [inline]
 netdev_start_xmit include/linux/netdevice.h:4520 [inline]
 xmit_one+0xfa/0x470 net/core/dev.c:3203
 dev_hard_start_xmit net/core/dev.c:3219 [inline]
 __dev_queue_xmit+0x1341/0x26b0 net/core/dev.c:3778
 packet_snd net/packet/af_packet.c:2988 [inline]
 packet_sendmsg+0x4d4d/0x6780 net/packet/af_packet.c:3013
 sock_sendmsg_nosec net/socket.c:638 [inline]
 sock_sendmsg net/socket.c:658 [inline]
 sock_write_iter+0x330/0x450 net/socket.c:990
 call_write_iter include/linux/fs.h:1971 [inline]
 new_sync_write fs/read_write.c:483 [inline]
 __vfs_write+0x5ec/0x780 fs/read_write.c:496
 vfs_write+0x212/0x4e0 fs/read_write.c:558
 ksys_write+0x186/0x2b0 fs/read_write.c:611
 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4665d9
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5b61e97188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000032 RSI: 0000000020000080 RDI: 0000000000000003
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffc6b08421f R14: 00007f5b61e97300 R15: 0000000000022000
Modules linked in:
CR2: ffff888240000000
---[ end trace 066d22568b4c776c ]---
RIP: 0010:do_csum arch/x86/lib/csum-partial_64.c:72 [inline]
RIP: 0010:csum_partial+0x194/0x470 arch/x86/lib/csum-partial_64.c:136
Code: 89 44 24 28 45 31 ff 48 8b 6c 24 08 66 2e 0f 1f 84 00 00 00 00 00 4c 03 6d 00 4c 13 6d 08 4c 13 6d 10 4c 13 6d 18 4c 13 6d 20 <4c> 13 6d 28 4c 13 6d 30 4c 13 6d 38 4d 11 fd 45 85 f6 74 0e 48 83
RSP: 0018:ffff8881c1767408 EFLAGS: 00010212
RAX: ffffffff84446971 RBX: 000000001ffffffd RCX: 0000000000040000
RDX: ffffc90008ca2000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffff88823fffffd8 R08: ffffffff84446911 R09: 0000000000000000
R10: ffffed103c04605d R11: 0000000000000000 R12: 00000000ffffffec
R13: 77968a9230221725 R14: 0000000002808c01 R15: 0000000000000000
FS:  00007f5b61e97700(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff888240000000 CR3: 00000001b008d000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400