bisecting fixing commit since 55f62bc873477dae2c45bbbc30b86cf3e0982f3b building syzkaller on a659b3f1dc889d5ab5ead017b877765b3d042379 testing commit 55f62bc873477dae2c45bbbc30b86cf3e0982f3b with gcc (GCC) 10.2.1 20210217 kernel signature: 6e4ddca735efc03149a665173b87ec015ce4bd3a550fa0a722ebf2f8c606d185 all runs: crashed: BUG: unable to handle kernel paging request in do_csum testing current HEAD c06a2ba62fc401b7aaefd23f5d0bc06d2457ccc1 testing commit c06a2ba62fc401b7aaefd23f5d0bc06d2457ccc1 with gcc (GCC) 10.2.1 20210217 kernel signature: 5652d02642f085ff066ed169393bd66f4e351482a4d9e441160c8187b0405ac7 all runs: crashed: BUG: unable to handle kernel paging request in do_csum revisions tested: 2, total time: 20m21.094393676s (build: 12m58.003079698s, test: 6m45.268657923s) the crash still happens on HEAD commit msg: Merge tag 'docs-5.13-3' of git://git.lwn.net/linux crash: BUG: unable to handle kernel paging request in do_csum BUG: unable to handle page fault for address: ffff8880bfffd000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD ec01067 P4D ec01067 PUD 23ffff067 PMD 23fffe067 PTE 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 10205 Comm: syz-executor.3 Not tainted 5.13.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:do_csum+0xc8/0x2e0 arch/x86/lib/csum-partial_64.c:72 Code: 8b 17 83 e8 01 83 ee 04 48 83 c7 04 48 01 d3 89 c1 c1 e8 04 d1 e9 85 c0 0f 84 cd 01 00 00 48 c1 e0 06 31 d2 48 01 f8 48 03 1f <48> 13 5f 08 48 13 5f 10 48 13 5f 18 48 13 5f 20 48 13 5f 28 48 13 RSP: 0018:ffffc9000ae77498 EFLAGS: 00010286 RAX: ffff888131363878 RBX: f55aca28094e8c5f RCX: 000000001ffffffd RDX: 0000000000000000 RSI: ffffffffffffffec RDI: ffff8880bfffcff8 RBP: 0000000000000000 R08: 0000000000000008 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888027270000 R13: ffff8880313638a4 R14: ffff8880313638b8 R15: ffff8880313638a4 FS: 00007f629f2a3700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8880bfffd000 CR3: 0000000025d69000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: csum_partial+0x8/0x10 arch/x86/lib/csum-partial_64.c:136 lco_csum include/linux/skbuff.h:4649 [inline] gre_build_header include/net/gre.h:139 [inline] __gre_xmit+0x7a0/0x940 net/ipv4/ip_gre.c:462 ipgre_xmit+0x5bf/0x790 net/ipv4/ip_gre.c:648 __netdev_start_xmit include/linux/netdevice.h:4944 [inline] netdev_start_xmit include/linux/netdevice.h:4958 [inline] xmit_one net/core/dev.c:3654 [inline] dev_hard_start_xmit+0x1a5/0x6f0 net/core/dev.c:3670 __dev_queue_xmit+0x1a42/0x26d0 net/core/dev.c:4245 packet_snd net/packet/af_packet.c:3009 [inline] packet_sendmsg+0x1e16/0x4840 net/packet/af_packet.c:3034 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg+0xab/0xe0 net/socket.c:674 sock_no_sendpage+0xe7/0x120 net/core/sock.c:2854 kernel_sendpage.part.0+0x11e/0x240 net/socket.c:3631 kernel_sendpage net/socket.c:3628 [inline] sock_sendpage+0xc7/0x1a0 net/socket.c:947 pipe_to_sendpage+0x245/0x410 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0x362/0x810 fs/splice.c:562 splice_from_pipe fs/splice.c:597 [inline] generic_splice_sendpage+0xba/0x120 fs/splice.c:746 do_splice_from fs/splice.c:767 [inline] do_splice+0x9fb/0x1b10 fs/splice.c:1079 __do_splice+0xf4/0x1b0 fs/splice.c:1144 __do_sys_splice fs/splice.c:1350 [inline] __se_sys_splice fs/splice.c:1332 [inline] __x64_sys_splice+0x14a/0x200 fs/splice.c:1332 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x465ef9 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:00007f629f2a3188 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000465ef9 RDX: 0000000000000006 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00000000004bcd1c R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008 R13: 00007fff3836bc0f R14: 00007f629f2a3300 R15: 0000000000022000 Modules linked in: CR2: ffff8880bfffd000 ---[ end trace 411947a2cbdcec60 ]--- RIP: 0010:do_csum+0xc8/0x2e0 arch/x86/lib/csum-partial_64.c:72 Code: 8b 17 83 e8 01 83 ee 04 48 83 c7 04 48 01 d3 89 c1 c1 e8 04 d1 e9 85 c0 0f 84 cd 01 00 00 48 c1 e0 06 31 d2 48 01 f8 48 03 1f <48> 13 5f 08 48 13 5f 10 48 13 5f 18 48 13 5f 20 48 13 5f 28 48 13 RSP: 0018:ffffc9000ae77498 EFLAGS: 00010286 RAX: ffff888131363878 RBX: f55aca28094e8c5f RCX: 000000001ffffffd RDX: 0000000000000000 RSI: ffffffffffffffec RDI: ffff8880bfffcff8 RBP: 0000000000000000 R08: 0000000000000008 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888027270000 R13: ffff8880313638a4 R14: ffff8880313638b8 R15: ffff8880313638a4 FS: 00007f629f2a3700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8880bfffd000 CR3: 0000000025d69000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400