Subject: WARNING in bpf_warn_invalid_xdp_action

From: syzbot <[email-masked]>
Date: Wed, 22 Jan 2020 08:09:09 -0800

Hello,

syzbot found the following crash on:

HEAD commit:    d0f41851 net, ip_tunnel: fix namespaces move
git tree:       net
console output: https://syzkaller.appspot.com/x/log.txt?x=10e94d85e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d9290aeb7e6cf1c4
dashboard link: https://syzkaller.appspot.com/bug?extid=8ce4113dadc4789fac74
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11f99369e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13d85601e00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: [email-masked]

------------[ cut here ]------------
Illegal XDP return value 4294967274, expect packet loss!
WARNING: CPU: 0 PID: 9780 at net/core/filter.c:6918 bpf_warn_invalid_xdp_action net/core/filter.c:6918 [inline]
WARNING: CPU: 0 PID: 9780 at net/core/filter.c:6918 bpf_warn_invalid_xdp_action+0x77/0x90 net/core/filter.c:6914
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 9780 Comm: syz-executor429 Not tainted 5.5.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x3e kernel/panic.c:582
 report_bug+0x289/0x300 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 fixup_bug arch/x86/kernel/traps.c:169 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:bpf_warn_invalid_xdp_action net/core/filter.c:6918 [inline]
RIP: 0010:bpf_warn_invalid_xdp_action+0x77/0x90 net/core/filter.c:6914
Code: 00 f9 d6 88 41 83 fc 04 48 c7 c6 40 f9 d6 88 4c 0f 46 ee e8 2b 9e 49 fb 44 89 e2 48 c7 c7 80 f9 d6 88 4c 89 ee e8 18 4e 1a fb <0f> 0b e8 12 9e 49 fb 5b 41 5c 41 5d 5d c3 90 66 2e 0f 1f 84 00 00
RSP: 0018:ffffc900000079a8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000100 RSI: ffffffff815e5326 RDI: fffff52000000f27
RBP: ffffc900000079c0 R08: ffff88809ff963c0 R09: ffffed1015d045c9
R10: ffffed1015d045c8 R11: ffff8880ae822e43 R12: 00000000ffffffea
R13: ffffffff88d6f900 R14: ffff8880927ea110 R15: ffff88809e257180
 netif_receive_generic_xdp net/core/dev.c:4564 [inline]
 do_xdp_generic.part.0+0xebb/0x1790 net/core/dev.c:4613
 do_xdp_generic net/core/dev.c:4985 [inline]
 __netif_receive_skb_core+0x68b/0x30b0 net/core/dev.c:4985
 __netif_receive_skb_one_core+0xa8/0x1a0 net/core/dev.c:5148
 __netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5264
 process_backlog+0x206/0x750 net/core/dev.c:6095
 napi_poll net/core/dev.c:6532 [inline]
 net_rx_action+0x508/0x1120 net/core/dev.c:6600
 __do_softirq+0x262/0x98c kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x19b/0x1e0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1137
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline]
RIP: 0010:console_unlock+0xbb8/0xf00 kernel/printk/printk.c:2481
Code: 93 89 48 c1 e8 03 42 80 3c 30 00 0f 85 e4 02 00 00 48 83 3d c1 43 35 08 00 0f 84 91 01 00 00 e8 3e 05 17 00 48 8b 7d 98 57 9d <0f> 1f 44 00 00 e9 6d ff ff ff e8 29 05 17 00 48 8b 7d 08 c7 05 1b
RSP: 0018:ffffc90001f26b38 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: ffff88809ff963c0 RBX: 0000000000000200 RCX: 0000000000000006
RDX: 0000000000000000 RSI: ffffffff815defe2 RDI: 0000000000000293
RBP: ffffc90001f26bc0 R08: 1ffffffff165e79c R09: fffffbfff165e79d
R10: fffffbfff165e79c R11: ffffffff8b2f3ce7 R12: 0000000000000000
R13: ffffffff84b35860 R14: dffffc0000000000 R15: ffffffff8a0fc990
 vprintk_emit+0x2a0/0x700 kernel/printk/printk.c:1996
 vprintk_default+0x28/0x30 kernel/printk/printk.c:2023
 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:386
 printk+0xba/0xed kernel/printk/printk.c:2056
 validate_nla lib/nlattr.c:178 [inline]
 __nla_validate_parse.cold+0x4d/0x60 lib/nlattr.c:381
 __nla_parse+0x43/0x60 lib/nlattr.c:478
 nla_parse_nested_deprecated include/net/netlink.h:1166 [inline]
 do_setlink+0x2ca2/0x3720 net/core/rtnetlink.c:2773
 rtnl_group_changelink net/core/rtnetlink.c:3089 [inline]
 __rtnl_newlink+0xdd2/0x1790 net/core/rtnetlink.c:3243
 rtnl_newlink+0x69/0xa0 net/core/rtnetlink.c:3363
 rtnetlink_rcv_msg+0x45e/0xaf0 net/core/rtnetlink.c:5424
 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5442
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x58c/0x7d0 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:639 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:659
 ____sys_sendmsg+0x753/0x880 net/socket.c:2330
 ___sys_sendmsg+0x100/0x170 net/socket.c:2384
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2417
 __do_sys_sendmsg net/socket.c:2426 [inline]
 __se_sys_sendmsg net/socket.c:2424 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2424
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x442af9
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 7b 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd3ded00a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000442af9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000003
RBP: 00007ffd3ded00c0 R08: 0000000001bbbbbb R09: 0000000001bbbbbb
R10: 0000000001bbbbbb R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000404090 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

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