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BUG: KMSAN: uninit-value in __skb_flow_dissect+0x60d3/0x8210 net/core/flow_dissector.c:1411
CPU: 1 PID: 11931 Comm: syz-executor.3 Not tainted 5.5.0-rc5-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+0x1c9/0x220 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 __skb_flow_dissect+0x60d3/0x8210 net/core/flow_dissector.c:1411
 skb_flow_dissect include/linux/skbuff.h:1293 [inline]
 fl_classify+0x3f5/0x1310 net/sched/cls_flower.c:319
 tcf_classify+0x280/0x700 net/sched/cls_api.c:1581
 hfsc_classify net/sched/sch_hfsc.c:1132 [inline]
 hfsc_enqueue+0x536/0x1700 net/sched/sch_hfsc.c:1539
 __dev_xmit_skb net/core/dev.c:3671 [inline]
 __dev_queue_xmit+0x20b3/0x4220 net/core/dev.c:3982
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4046
 neigh_resolve_output+0xab0/0xb40 net/core/neighbour.c:1487
 neigh_output include/net/neighbour.h:510 [inline]
 ip_finish_output2+0x1acc/0x2610 net/ipv4/ip_output.c:228
 __ip_finish_output+0xaa7/0xd80 net/ipv4/ip_output.c:308
 ip_finish_output+0x166/0x410 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip_output+0x593/0x680 net/ipv4/ip_output.c:432
 dst_output include/net/dst.h:436 [inline]
 ip_local_out net/ipv4/ip_output.c:125 [inline]
 __ip_queue_xmit+0x1b5f/0x21b0 net/ipv4/ip_output.c:532
 ip_queue_xmit include/net/ip.h:237 [inline]
 l2tp_ip_sendmsg+0x1478/0x1870 net/l2tp/l2tp_ip.c:493
 inet_sendmsg+0x2d8/0x2e0 net/ipv4/af_inet.c:807
 sock_sendmsg_nosec net/socket.c:639 [inline]
 sock_sendmsg net/socket.c:659 [inline]
 ____sys_sendmsg+0x1056/0x1350 net/socket.c:2330
 ___sys_sendmsg net/socket.c:2384 [inline]
 __sys_sendmmsg+0x5b6/0xc90 net/socket.c:2474
 __do_sys_sendmmsg net/socket.c:2503 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2500
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2500
 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45b349
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f3f906bdc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f3f906be6d4 RCX: 000000000045b349
RDX: 0000000000000002 RSI: 00000000200007c0 RDI: 0000000000000004
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000008cc R14: 00000000004ca20c R15: 000000000075bf2c

Local variable ----skb_key@fl_classify created at:
 fl_classify+0xd4/0x1310 net/sched/cls_flower.c:303
 fl_classify+0xd4/0x1310 net/sched/cls_flower.c:303
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