===================================================== BUG: KMSAN: uninit-value in __skb_flow_dissect+0x5153/0x8070 net/core/flow_dissector.c:1418 CPU: 0 PID: 18631 Comm: syz-executor.5 Not tainted 5.6.0-rc2-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+0x5153/0x8070 net/core/flow_dissector.c:1418 skb_flow_dissect include/linux/skbuff.h:1295 [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:3721 [inline] __dev_queue_xmit+0x20b3/0x4220 net/core/dev.c:4032 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4096 neigh_direct_output+0x42/0x50 net/core/neighbour.c:1527 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:306 ip_finish_output+0x166/0x410 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0x593/0x680 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:436 [inline] ip_local_out net/ipv4/ip_output.c:125 [inline] __ip_queue_xmit+0x1b5c/0x21a0 net/ipv4/ip_output.c:530 ip_queue_xmit+0xcc/0xf0 include/net/ip.h:237 __tcp_transmit_skb+0x439c/0x6090 net/ipv4/tcp_output.c:1234 tcp_transmit_skb net/ipv4/tcp_output.c:1250 [inline] tcp_write_xmit+0x30e1/0xb470 net/ipv4/tcp_output.c:2513 __tcp_push_pending_frames+0x124/0x4e0 net/ipv4/tcp_output.c:2689 tcp_push+0x6fa/0x8a0 net/ipv4/tcp.c:725 tcp_sendmsg_locked+0x5d89/0x6d00 net/ipv4/tcp.c:1403 tcp_sendmsg+0xb2/0x100 net/ipv4/tcp.c:1433 inet_sendmsg+0x178/0x2e0 net/ipv4/af_inet.c:807 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x1056/0x1350 net/socket.c:2343 ___sys_sendmsg net/socket.c:2397 [inline] __sys_sendmmsg+0x5b6/0xc90 net/socket.c:2487 __do_sys_sendmmsg net/socket.c:2516 [inline] __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2513 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2513 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c449 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:00007f12ccb33c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f12ccb346d4 RCX: 000000000045c449 RDX: 0000000000000002 RSI: 0000000020003b40 RDI: 0000000000000003 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000004000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008d4 R14: 00000000004cb363 R15: 000000000076bf2c 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 =====================================================