bisecting fixing commit since 6dd0e32665e591e9debe3edaf73c2f8135bf047e
building syzkaller on 17a986e54c507287c078a70fa9eea0be9f191f84
testing commit 6dd0e32665e591e9debe3edaf73c2f8135bf047e with gcc (GCC) 8.1.0
kernel signature: b7f85cffd3306d0aa419c86d7f3dd167b4ba99e9c2cbda8ce39ae728c9a7e73c
all runs: crashed: WARNING in bpf_warn_invalid_xdp_action
testing current HEAD 3fc898571b974f9a05e4e5c1fe17b18548207091
testing commit 3fc898571b974f9a05e4e5c1fe17b18548207091 with gcc (GCC) 8.1.0
kernel signature: 8f60969db8848715bf999ad4ae7f0f5b5c62201b3752c3322763732af62a75a6
all runs: crashed: WARNING in bpf_warn_invalid_xdp_action
revisions tested: 2, total time: 25m49.113876058s (build: 18m49.30142039s, test: 6m17.840893014s)
the crash still happens on HEAD
commit msg: Linux 4.19.128
crash: WARNING in bpf_warn_invalid_xdp_action
batman_adv: batadv0: Interface activated: batadv_slave_1
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
------------[ cut here ]------------
Illegal XDP return value 1657869714, expect packet loss!
WARNING: CPU: 1 PID: 18 at net/core/filter.c:5537 bpf_warn_invalid_xdp_action+0x38/0x40 net/core/filter.c:5535
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 18 Comm: ksoftirqd/1 Not tainted 4.19.128-syzkaller #0
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+0x123/0x177 lib/dump_stack.c:118
 panic+0x1cd/0x375 kernel/panic.c:186
 __warn.cold.8+0x1b/0x3e kernel/panic.c:541
 report_bug+0x1a4/0x200 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x200/0x350 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038
RIP: 0010:bpf_warn_invalid_xdp_action+0x38/0x40 net/core/filter.c:5535
Code: c7 c0 a0 1f c0 87 55 89 fa 48 c7 c6 60 1f c0 87 48 89 e5 48 c7 c7 e0 1f c0 87 c6 05 d8 fb b1 03 01 48 0f 46 f0 e8 9b 96 ce fb <0f> 0b 5d c3 0f 1f 40 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 e5
RSP: 0018:ffff8880a9867ae0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff8880a482edc6 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff87677580 RDI: ffffffff8a186960
RBP: ffff8880a9867ae0 R08: ffffed1015d65079 R09: ffffed1015d65078
R10: ffffed1015d65078 R11: ffff8880aeb283c7 R12: ffff8880a482ed00
R13: dffffc0000000000 R14: ffff8880a482f146 R15: ffff8880a482ed00
 veth_xdp_rcv_skb drivers/net/veth.c:551 [inline]
 veth_xdp_rcv drivers/net/veth.c:602 [inline]
 veth_poll+0x1035/0x2ea0 drivers/net/veth.c:622
 napi_poll net/core/dev.c:6277 [inline]
 net_rx_action+0x470/0xe20 net/core/dev.c:6343
 __do_softirq+0x260/0x92d kernel/softirq.c:292
 run_ksoftirqd+0x94/0x100 kernel/softirq.c:653
 smpboot_thread_fn+0x55f/0x8a0 kernel/smpboot.c:164
 kthread+0x324/0x3e0 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Kernel Offset: disabled
Rebooting in 86400 seconds..