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BUG: KMSAN: uninit-value in ip6t_mangle_out net/ipv6/netfilter/ip6table_mangle.c:56 [inline]
BUG: KMSAN: uninit-value in ip6table_mangle_hook+0xa70/0xad0 net/ipv6/netfilter/ip6table_mangle.c:72
 ip6t_mangle_out net/ipv6/netfilter/ip6table_mangle.c:56 [inline]
 ip6table_mangle_hook+0xa70/0xad0 net/ipv6/netfilter/ip6table_mangle.c:72
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xe1/0x3d0 net/netfilter/core.c:623
 nf_hook include/linux/netfilter.h:273 [inline]
 __ip6_local_out+0x616/0x6b0 net/ipv6/output_core.c:145
 ip6_local_out+0x4b/0x250 net/ipv6/output_core.c:155
 ip6tunnel_xmit+0x11d/0x460 include/net/ip6_tunnel.h:162
 ip6_tnl_xmit+0x3711/0x39b0 net/ipv6/ip6_tunnel.c:1280
 __gre6_xmit+0x97c/0x1430 net/ipv6/ip6_gre.c:786
 ip6gre_xmit_ipv4 net/ipv6/ip6_gre.c:810 [inline]
 ip6gre_tunnel_xmit+0xf60/0x1cf0 net/ipv6/ip6_gre.c:893
 __netdev_start_xmit include/linux/netdevice.h:5273 [inline]
 netdev_start_xmit include/linux/netdevice.h:5282 [inline]
 xmit_one net/core/dev.c:3866 [inline]
 dev_hard_start_xmit+0x22f/0xa30 net/core/dev.c:3882
 sch_direct_xmit+0x3b2/0xcf0 net/sched/sch_generic.c:347
 __dev_xmit_skb net/core/dev.c:4182 [inline]
 __dev_queue_xmit+0x2f67/0x58c0 net/core/dev.c:4798
 dev_queue_xmit include/linux/netdevice.h:3381 [inline]
 packet_xmit+0x8f/0x710 net/packet/af_packet.c:275
 packet_snd net/packet/af_packet.c:3076 [inline]
 packet_sendmsg+0x9173/0xa2a0 net/packet/af_packet.c:3108
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x333/0x3d0 net/socket.c:742
 __sys_sendto+0x593/0x720 net/socket.c:2206
 __do_sys_sendto net/socket.c:2213 [inline]
 __se_sys_sendto net/socket.c:2209 [inline]
 __x64_sys_sendto+0x130/0x200 net/socket.c:2209
 x64_sys_call+0x332b/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd3/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was stored to memory at:
 ip6_tnl_xmit+0x37f0/0x39b0 net/ipv6/ip6_tunnel.c:1276
 __gre6_xmit+0x97c/0x1430 net/ipv6/ip6_gre.c:786
 ip6gre_xmit_ipv4 net/ipv6/ip6_gre.c:810 [inline]
 ip6gre_tunnel_xmit+0xf60/0x1cf0 net/ipv6/ip6_gre.c:893
 __netdev_start_xmit include/linux/netdevice.h:5273 [inline]
 netdev_start_xmit include/linux/netdevice.h:5282 [inline]
 xmit_one net/core/dev.c:3866 [inline]
 dev_hard_start_xmit+0x22f/0xa30 net/core/dev.c:3882
 sch_direct_xmit+0x3b2/0xcf0 net/sched/sch_generic.c:347
 __dev_xmit_skb net/core/dev.c:4182 [inline]
 __dev_queue_xmit+0x2f67/0x58c0 net/core/dev.c:4798
 dev_queue_xmit include/linux/netdevice.h:3381 [inline]
 packet_xmit+0x8f/0x710 net/packet/af_packet.c:275
 packet_snd net/packet/af_packet.c:3076 [inline]
 packet_sendmsg+0x9173/0xa2a0 net/packet/af_packet.c:3108
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x333/0x3d0 net/socket.c:742
 __sys_sendto+0x593/0x720 net/socket.c:2206
 __do_sys_sendto net/socket.c:2213 [inline]
 __se_sys_sendto net/socket.c:2209 [inline]
 __x64_sys_sendto+0x130/0x200 net/socket.c:2209
 x64_sys_call+0x332b/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd3/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4960 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 __do_kmalloc_node mm/slub.c:5656 [inline]
 __kmalloc_node_track_caller_noprof+0xb77/0x1c90 mm/slub.c:5764
 kmalloc_reserve+0x22f/0x4b0 net/core/skbuff.c:608
 pskb_expand_head+0x1fc/0x15d0 net/core/skbuff.c:2282
 skb_realloc_headroom+0x152/0x2d0 net/core/skbuff.c:2360
 ip6_tnl_xmit+0x2177/0x39b0 net/ipv6/ip6_tunnel.c:1227
 __gre6_xmit+0x97c/0x1430 net/ipv6/ip6_gre.c:786
 ip6gre_xmit_ipv4 net/ipv6/ip6_gre.c:810 [inline]
 ip6gre_tunnel_xmit+0xf60/0x1cf0 net/ipv6/ip6_gre.c:893
 __netdev_start_xmit include/linux/netdevice.h:5273 [inline]
 netdev_start_xmit include/linux/netdevice.h:5282 [inline]
 xmit_one net/core/dev.c:3866 [inline]
 dev_hard_start_xmit+0x22f/0xa30 net/core/dev.c:3882
 sch_direct_xmit+0x3b2/0xcf0 net/sched/sch_generic.c:347
 __dev_xmit_skb net/core/dev.c:4182 [inline]
 __dev_queue_xmit+0x2f67/0x58c0 net/core/dev.c:4798
 dev_queue_xmit include/linux/netdevice.h:3381 [inline]
 packet_xmit+0x8f/0x710 net/packet/af_packet.c:275
 packet_snd net/packet/af_packet.c:3076 [inline]
 packet_sendmsg+0x9173/0xa2a0 net/packet/af_packet.c:3108
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x333/0x3d0 net/socket.c:742
 __sys_sendto+0x593/0x720 net/socket.c:2206
 __do_sys_sendto net/socket.c:2213 [inline]
 __se_sys_sendto net/socket.c:2209 [inline]
 __x64_sys_sendto+0x130/0x200 net/socket.c:2209
 x64_sys_call+0x332b/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd3/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 1 UID: 0 PID: 6447 Comm: syz.0.15 Not tainted syzkaller #0 PREEMPT(none) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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