general protection fault in em_u32_match (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15b62b16480000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=b13ecef30148e3980463
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14368186480000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14de2089480000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/98c0bdb4abb3/disk-3f8a27f9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ea228ff02669/vmlinux-3f8a27f9.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b13ece...@syzkaller.appspotmail.com

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
CPU: 1 PID: 8301 Comm: kworker/1:3 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:em_u32_match+0x156/0x300 net/sched/em_u32.c:33
Code: 9c 01 00 00 41 23 5c 24 0c 48 63 db 4c 01 fb e8 40 da c2 fa 49 8d 7c 24 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 21
RSP: 0018:ffff888094fe6bc8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8880b3b11cde RCX: ffffffff869f8a05
RDX: 0000000000000001 RSI: ffffffff869fab30 RDI: 0000000000000008
RBP: ffff8880ab743c00 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000004 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8880b3b11cc0 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd308274f8 CR3: 0000000009e6d000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
tcf_em_match net/sched/ematch.c:496 [inline]
__tcf_em_tree_match+0x14a/0x530 net/sched/ematch.c:522
tcf_em_tree_match include/net/pkt_cls.h:531 [inline]
basic_classify+0x1c0/0x2b0 net/sched/cls_basic.c:49
tcf_classify+0x120/0x3c0 net/sched/cls_api.c:979
prio_classify net/sched/sch_prio.c:46 [inline]
prio_enqueue+0x3bb/0x7a0 net/sched/sch_prio.c:78
__dev_xmit_skb net/core/dev.c:3494 [inline]
__dev_queue_xmit+0x140a/0x2e00 net/core/dev.c:3807
neigh_hh_output include/net/neighbour.h:491 [inline]
neigh_output include/net/neighbour.h:499 [inline]
ip_finish_output2+0xb6d/0x15a0 net/ipv4/ip_output.c:230
ip_finish_output+0xae9/0x10b0 net/ipv4/ip_output.c:318
NF_HOOK_COND include/linux/netfilter.h:278 [inline]
ip_output+0x203/0x5f0 net/ipv4/ip_output.c:406
dst_output include/net/dst.h:455 [inline]
ip_local_out+0xaf/0x170 net/ipv4/ip_output.c:125
iptunnel_xmit+0x63b/0x9d0 net/ipv4/ip_tunnel_core.c:91
geneve_xmit_skb drivers/net/geneve.c:867 [inline]
geneve_xmit+0x120d/0x2e60 drivers/net/geneve.c:943
__netdev_start_xmit include/linux/netdevice.h:4349 [inline]
netdev_start_xmit include/linux/netdevice.h:4363 [inline]
xmit_one net/core/dev.c:3256 [inline]
dev_hard_start_xmit+0x1a8/0x920 net/core/dev.c:3272
__dev_queue_xmit+0x269d/0x2e00 net/core/dev.c:3838
neigh_resolve_output+0x55a/0x910 net/core/neighbour.c:1374
neigh_output include/net/neighbour.h:501 [inline]
ip6_finish_output2+0x113d/0x2290 net/ipv6/ip6_output.c:120
ip6_finish_output+0x89b/0x10f0 net/ipv6/ip6_output.c:192
NF_HOOK_COND include/linux/netfilter.h:278 [inline]
ip6_output+0x205/0x770 net/ipv6/ip6_output.c:209
dst_output include/net/dst.h:455 [inline]
NF_HOOK include/linux/netfilter.h:289 [inline]
ndisc_send_skb+0xa24/0x1720 net/ipv6/ndisc.c:491
ndisc_send_ns+0x51d/0x840 net/ipv6/ndisc.c:633
addrconf_dad_work+0xb0e/0x10a0 net/ipv6/addrconf.c:4076
process_one_work+0x864/0x1570 kernel/workqueue.c:2153
worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Modules linked in:
---[ end trace 4a630fdc4567183b ]---
RIP: 0010:em_u32_match+0x156/0x300 net/sched/em_u32.c:33
Code: 9c 01 00 00 41 23 5c 24 0c 48 63 db 4c 01 fb e8 40 da c2 fa 49 8d 7c 24 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 21
RSP: 0018:ffff888094fe6bc8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8880b3b11cde RCX: ffffffff869f8a05
RDX: 0000000000000001 RSI: ffffffff869fab30 RDI: 0000000000000008
RBP: ffff8880ab743c00 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000004 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8880b3b11cc0 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd308274f8 CR3: 0000000009e6d000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 9c pushfq
1: 01 00 add %eax,(%rax)
3: 00 41 23 add %al,0x23(%rcx)
6: 5c pop %rsp
7: 24 0c and $0xc,%al
9: 48 63 db movslq %ebx,%rbx
c: 4c 01 fb add %r15,%rbx
f: e8 40 da c2 fa callq 0xfac2da54
14: 49 8d 7c 24 08 lea 0x8(%r12),%rdi
19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
20: fc ff df
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx <-- trapping instruction
2e: 48 89 f8 mov %rdi,%rax
31: 83 e0 07 and $0x7,%eax
34: 83 c0 03 add $0x3,%eax
37: 38 d0 cmp %dl,%al
39: 7c 08 jl 0x43
3b: 84 d2 test %dl,%dl
3d: 0f .byte 0xf
3e: 85 21 test %esp,(%rcx)


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