===================================================== BUG: KMSAN: uninit-value in __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline] BUG: KMSAN: uninit-value in __fswab32 include/uapi/linux/swab.h:60 [inline] BUG: KMSAN: uninit-value in gre_parse_header+0x1b2d/0x1e70 net/ipv4/gre_demux.c:139 CPU: 0 PID: 13163 Comm: syz-executor.0 Not tainted 5.10.0-rc4-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+0x21c/0x280 lib/dump_stack.c:118 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197 __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline] __fswab32 include/uapi/linux/swab.h:60 [inline] gre_parse_header+0x1b2d/0x1e70 net/ipv4/gre_demux.c:139 gre_rcv+0x203/0x1e90 net/ipv4/ip_gre.c:431 gre_rcv+0x321/0x410 net/ipv4/gre_demux.c:163 ip_protocol_deliver_rcu+0x572/0xc50 net/ipv4/ip_input.c:204 ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ip_local_deliver+0x585/0x8d0 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:449 [inline] ip_rcv_finish net/ipv4/ip_input.c:428 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ip_rcv+0x599/0x820 net/ipv4/ip_input.c:539 __netif_receive_skb_one_core net/core/dev.c:5315 [inline] __netif_receive_skb+0x1ec/0x640 net/core/dev.c:5429 process_backlog+0x517/0xbd0 net/core/dev.c:6319 napi_poll+0x40a/0x1020 net/core/dev.c:6763 net_rx_action+0x34c/0xd30 net/core/dev.c:6833 __do_softirq+0x1a9/0x6fa kernel/softirq.c:298 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0x6e/0x90 arch/x86/kernel/irq_64.c:77 do_softirq kernel/softirq.c:343 [inline] __local_bh_enable_ip+0x184/0x1d0 kernel/softirq.c:195 local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32 rcu_read_unlock_bh include/linux/rcupdate.h:730 [inline] ip_finish_output2+0x2454/0x2940 net/ipv4/ip_output.c:231 ip_do_fragment+0x3675/0x3b50 net/ipv4/ip_output.c:857 ip_fragment+0x31e/0x4b0 net/ipv4/ip_output.c:593 __ip_finish_output+0x1023/0x1090 net/ipv4/ip_output.c:306 ip_finish_output+0x329/0x480 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip_output+0x32e/0x6d0 net/ipv4/ip_output.c:432 dst_output include/net/dst.h:443 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] ip_send_skb+0x194/0x350 net/ipv4/ip_output.c:1568 udp_send_skb+0x152d/0x1bc0 net/ipv4/udp.c:948 udp_push_pending_frames net/ipv4/udp.c:976 [inline] udp_sendmsg+0xb98/0x48f0 net/ipv4/udp.c:1267 inet_sendmsg+0x15b/0x1d0 net/ipv4/af_inet.c:817 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg net/socket.c:671 [inline] sock_write_iter+0x585/0x680 net/socket.c:998 call_write_iter include/linux/fs.h:1903 [inline] new_sync_write fs/read_write.c:518 [inline] vfs_write+0x1083/0x1b00 fs/read_write.c:605 ksys_write+0x275/0x500 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write+0x92/0xb0 fs/read_write.c:667 __x64_sys_write+0x4a/0x70 fs/read_write.c:667 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x465b09 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4ba8f1f188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 000000000000fdef RSI: 0000000020000280 RDI: 0000000000000006 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 0000000000a9fb1f R14: 00007f4ba8f1f300 R15: 0000000000022000 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline] kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:289 kmsan_memcpy_memmove_metadata+0x25e/0x2d0 mm/kmsan/kmsan.c:226 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:246 __msan_memcpy+0x46/0x60 mm/kmsan/kmsan_instr.c:110 pskb_expand_head+0x3d6/0x1e20 net/core/skbuff.c:1631 __skb_cow include/linux/skbuff.h:3165 [inline] skb_cow_head include/linux/skbuff.h:3199 [inline] ip_tunnel_xmit+0x3010/0x3a80 net/ipv4/ip_tunnel.c:800 __gre_xmit net/ipv4/ip_gre.c:466 [inline] erspan_xmit+0x20c6/0x3260 net/ipv4/ip_gre.c:702 __netdev_start_xmit include/linux/netdevice.h:4718 [inline] netdev_start_xmit include/linux/netdevice.h:4732 [inline] xmit_one+0x2b6/0x760 net/core/dev.c:3564 dev_hard_start_xmit+0x196/0x420 net/core/dev.c:3580 sch_direct_xmit+0x57c/0x1a60 net/sched/sch_generic.c:314 qdisc_restart net/sched/sch_generic.c:377 [inline] __qdisc_run+0x35b/0x490 net/sched/sch_generic.c:385 qdisc_run include/net/pkt_sched.h:131 [inline] __dev_xmit_skb net/core/dev.c:3755 [inline] __dev_queue_xmit+0x26a1/0x4590 net/core/dev.c:4108 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4173 neigh_resolve_output+0xc65/0xcf0 net/core/neighbour.c:1489 neigh_output include/net/neighbour.h:509 [inline] ip_finish_output2+0x1d18/0x2940 net/ipv4/ip_output.c:230 ip_do_fragment+0x3675/0x3b50 net/ipv4/ip_output.c:857 ip_fragment+0x31e/0x4b0 net/ipv4/ip_output.c:593 __ip_finish_output+0x1023/0x1090 net/ipv4/ip_output.c:306 ip_finish_output+0x329/0x480 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip_output+0x32e/0x6d0 net/ipv4/ip_output.c:432 dst_output include/net/dst.h:443 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] ip_send_skb+0x194/0x350 net/ipv4/ip_output.c:1568 udp_send_skb+0x152d/0x1bc0 net/ipv4/udp.c:948 udp_push_pending_frames net/ipv4/udp.c:976 [inline] udp_sendmsg+0xb98/0x48f0 net/ipv4/udp.c:1267 inet_sendmsg+0x15b/0x1d0 net/ipv4/af_inet.c:817 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg net/socket.c:671 [inline] sock_write_iter+0x585/0x680 net/socket.c:998 call_write_iter include/linux/fs.h:1903 [inline] new_sync_write fs/read_write.c:518 [inline] vfs_write+0x1083/0x1b00 fs/read_write.c:605 ksys_write+0x275/0x500 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write+0x92/0xb0 fs/read_write.c:667 __x64_sys_write+0x4a/0x70 fs/read_write.c:667 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline] kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:104 kmsan_slab_alloc+0x8d/0xe0 mm/kmsan/kmsan_hooks.c:76 slab_alloc_node mm/slub.c:2906 [inline] __kmalloc_node_track_caller+0xa48/0x1610 mm/slub.c:4512 __kmalloc_reserve net/core/skbuff.c:142 [inline] __alloc_skb+0x318/0xb00 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1094 [inline] alloc_skb_with_frags+0x1f3/0xc10 net/core/skbuff.c:5832 sock_alloc_send_pskb+0xcc4/0xe80 net/core/sock.c:2329 sock_alloc_send_skb+0xca/0xe0 net/core/sock.c:2346 __ip_append_data+0x455d/0x62f0 net/ipv4/ip_output.c:1097 ip_append_data+0x344/0x4c0 net/ipv4/ip_output.c:1323 udp_sendmsg+0x7b9/0x48f0 net/ipv4/udp.c:1261 inet_sendmsg+0x15b/0x1d0 net/ipv4/af_inet.c:817 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg net/socket.c:671 [inline] ____sys_sendmsg+0xcfc/0x12f0 net/socket.c:2353 ___sys_sendmsg net/socket.c:2407 [inline] __sys_sendmsg+0x6f1/0x840 net/socket.c:2440 __do_sys_sendmsg net/socket.c:2449 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48 entry_SYSCALL_64_after_hwframe+0x44/0xa9 =====================================================