bisecting fixing commit since 2c8a3fceddf0dd87f278e7a5e01350f86f844b1c
building syzkaller on 0655e081f42239d4eca4345ef7293307085f78f5
testing commit 2c8a3fceddf0dd87f278e7a5e01350f86f844b1c with gcc (GCC) 8.4.1 20210217
kernel signature: cf4cf634caa7625fcfb66770acbce7500819de427e4abcdb4fe76de3faf1a666
all runs: crashed: general protection fault in vxlan_fdb_destroy
testing current HEAD 958e517f4e16952e9a2e2d58fd32d28ae4e23dda
testing commit 958e517f4e16952e9a2e2d58fd32d28ae4e23dda with gcc (GCC) 8.4.1 20210217
kernel signature: 577d40acac85417b31793cd2681bc1714463dbb4264a3bd6e23466b9f459aa58
all runs: crashed: general protection fault in vxlan_fdb_destroy
revisions tested: 2, total time: 21m24.7016731s (build: 14m37.028899982s, test: 6m13.549969735s)
the crash still happens on HEAD
commit msg: Linux 4.14.230
crash: general protection fault in vxlan_fdb_destroy
netlink: 20 bytes leftover after parsing attributes in process `syz-executor.3'.
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.3'.
IPv6: ADDRCONF(NETDEV_UP): veth0_to_batadv: link is not ready
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 9665 Comm: syz-executor.3 Not tainted 4.14.230-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff888098da2180 task.stack: ffff88808d4f8000
RIP: 0010:__write_once_size include/linux/compiler.h:210 [inline]
RIP: 0010:__hlist_del include/linux/list.h:679 [inline]
RIP: 0010:hlist_del_rcu include/linux/rculist.h:427 [inline]
RIP: 0010:vxlan_fdb_destroy+0xa8/0x1e0 drivers/net/vxlan.c:787
RSP: 0018:ffff88808d4fef88 EFLAGS: 00010a02
RAX: dffffc0000000000 RBX: ffff88809ac6be00 RCX: 0000000000000000
RDX: 1bd5a00000000040 RSI: ffff88809ac6be00 RDI: ffff88809ac6be08
RBP: ffff88808d4fefa8 R08: ffff888098da2a50 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: dead000000000200 R14: ffff88808d4ff078 R15: 00000000fffffff0
FS:  00007efef67b7700(0000) GS:ffff8880ba600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd001eff10 CR3: 000000009bbd9000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __vxlan_dev_create+0x3a9/0x740 drivers/net/vxlan.c:3281
 vxlan_newlink+0x99/0xd0 drivers/net/vxlan.c:3502
 rtnl_newlink+0xcc9/0x1630 net/core/rtnetlink.c:2728
 rtnetlink_rcv_msg+0x34c/0x9e0 net/core/rtnetlink.c:4316
 netlink_rcv_skb+0x12f/0x3b0 net/netlink/af_netlink.c:2433
 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4328
 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
 netlink_unicast+0x40b/0x610 net/netlink/af_netlink.c:1313
 netlink_sendmsg+0x639/0xbe0 net/netlink/af_netlink.c:1878
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xac/0xf0 net/socket.c:656
 kernel_sendmsg+0x26/0x30 net/socket.c:664
 sock_no_sendpage+0xf7/0x130 net/core/sock.c:2595
 kernel_sendpage+0x60/0xd0 net/socket.c:3407
 sock_sendpage+0x6d/0xd0 net/socket.c:871
 pipe_to_sendpage+0x206/0x420 fs/splice.c:451
 splice_from_pipe_feed fs/splice.c:502 [inline]
 __splice_from_pipe+0x2cb/0x720 fs/splice.c:626
 splice_from_pipe+0xb5/0x110 fs/splice.c:661
 generic_splice_sendpage+0x10/0x20 fs/splice.c:832
 do_splice_from fs/splice.c:851 [inline]
 do_splice fs/splice.c:1147 [inline]
 SYSC_splice fs/splice.c:1402 [inline]
 SyS_splice+0x6f1/0x1590 fs/splice.c:1382
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x465b09
RSP: 002b:00007efef67b7188 EFLAGS: 00000246 ORIG_RAX: 0000000000000113
RAX: ffffffffffffffda RBX: 000000000056c0b0 RCX: 0000000000465b09
RDX: 0000000000000006 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00000000004b069f R08: 000000000004ffe2 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c0b0
R13: 00007fffa4a5045f R14: 00007efef67b7300 R15: 0000000000022000
Code: 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 12 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 6b 08 4c 89 ea 48 c1 ea 03 <80> 3c 02 00 0f 85 e6 00 00 00 4d 85 e4 4d 89 65 00 74 25 49 8d 
RIP: __write_once_size include/linux/compiler.h:210 [inline] RSP: ffff88808d4fef88
RIP: __hlist_del include/linux/list.h:679 [inline] RSP: ffff88808d4fef88
RIP: hlist_del_rcu include/linux/rculist.h:427 [inline] RSP: ffff88808d4fef88
RIP: vxlan_fdb_destroy+0xa8/0x1e0 drivers/net/vxlan.c:787 RSP: ffff88808d4fef88
---[ end trace 0878b1d21ad16dee ]---