===================================================== BUG: KMSAN: uninit-value in ipt_mangle_out net/ipv4/netfilter/iptable_mangle.c:61 [inline] BUG: KMSAN: uninit-value in iptable_mangle_hook+0x75a/0x8c0 net/ipv4/netfilter/iptable_mangle.c:81 CPU: 1 PID: 21709 Comm: syz-executor.4 Tainted: G W 5.12.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x24c/0x2e0 lib/dump_stack.c:120 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:121 __msan_warning+0x5c/0xa0 mm/kmsan/kmsan_instr.c:197 ipt_mangle_out net/ipv4/netfilter/iptable_mangle.c:61 [inline] iptable_mangle_hook+0x75a/0x8c0 net/ipv4/netfilter/iptable_mangle.c:81 nf_hook_entry_hookfn include/linux/netfilter.h:136 [inline] nf_hook_slow+0x17b/0x460 net/netfilter/core.c:589 nf_hook include/linux/netfilter.h:256 [inline] __ip_local_out+0x78c/0x840 net/ipv4/ip_output.c:115 ip_local_out+0xa1/0x1e0 net/ipv4/ip_output.c:124 iptunnel_xmit+0x931/0xf20 net/ipv4/ip_tunnel_core.c:82 udp_tunnel_xmit_skb+0x526/0x640 net/ipv4/udp_tunnel_core.c:174 geneve_xmit_skb drivers/net/geneve.c:959 [inline] geneve_xmit+0x2139/0x3c40 drivers/net/geneve.c:1059 __netdev_start_xmit include/linux/netdevice.h:4825 [inline] netdev_start_xmit include/linux/netdevice.h:4839 [inline] xmit_one+0x2b6/0x760 net/core/dev.c:3605 dev_hard_start_xmit net/core/dev.c:3621 [inline] __dev_queue_xmit+0x3432/0x4600 net/core/dev.c:4194 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4227 packet_snd net/packet/af_packet.c:3006 [inline] packet_sendmsg+0x86ee/0x99d0 net/packet/af_packet.c:3031 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg net/socket.c:674 [inline] ____sys_sendmsg+0xcfc/0x12f0 net/socket.c:2350 ___sys_sendmsg net/socket.c:2404 [inline] __sys_sendmsg+0x714/0x830 net/socket.c:2433 __compat_sys_sendmsg net/compat.c:347 [inline] __do_compat_sys_sendmsg net/compat.c:354 [inline] __se_compat_sys_sendmsg+0xa7/0xc0 net/compat.c:351 __ia32_compat_sys_sendmsg+0x4a/0x70 net/compat.c:351 do_syscall_32_irqs_on arch/x86/entry/common.c:79 [inline] __do_fast_syscall_32+0x127/0x180 arch/x86/entry/common.c:142 do_fast_syscall_32+0x77/0xd0 arch/x86/entry/common.c:168 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:211 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf7ffc549 Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f55f65fc EFLAGS: 00000296 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000500 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 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 __msan_chain_origin+0x54/0xa0 mm/kmsan/kmsan_instr.c:147 iptunnel_xmit+0xbd6/0xf20 net/ipv4/ip_tunnel_core.c:76 udp_tunnel_xmit_skb+0x526/0x640 net/ipv4/udp_tunnel_core.c:174 geneve_xmit_skb drivers/net/geneve.c:959 [inline] geneve_xmit+0x2139/0x3c40 drivers/net/geneve.c:1059 __netdev_start_xmit include/linux/netdevice.h:4825 [inline] netdev_start_xmit include/linux/netdevice.h:4839 [inline] xmit_one+0x2b6/0x760 net/core/dev.c:3605 dev_hard_start_xmit net/core/dev.c:3621 [inline] __dev_queue_xmit+0x3432/0x4600 net/core/dev.c:4194 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4227 packet_snd net/packet/af_packet.c:3006 [inline] packet_sendmsg+0x86ee/0x99d0 net/packet/af_packet.c:3031 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg net/socket.c:674 [inline] ____sys_sendmsg+0xcfc/0x12f0 net/socket.c:2350 ___sys_sendmsg net/socket.c:2404 [inline] __sys_sendmsg+0x714/0x830 net/socket.c:2433 __compat_sys_sendmsg net/compat.c:347 [inline] __do_compat_sys_sendmsg net/compat.c:354 [inline] __se_compat_sys_sendmsg+0xa7/0xc0 net/compat.c:351 __ia32_compat_sys_sendmsg+0x4a/0x70 net/compat.c:351 do_syscall_32_irqs_on arch/x86/entry/common.c:79 [inline] __do_fast_syscall_32+0x127/0x180 arch/x86/entry/common.c:142 do_fast_syscall_32+0x77/0xd0 arch/x86/entry/common.c:168 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:211 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c 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+0x8e/0xe0 mm/kmsan/kmsan_hooks.c:76 slab_alloc_node mm/slub.c:2922 [inline] __kmalloc_node_track_caller+0xa4f/0x1470 mm/slub.c:4609 kmalloc_reserve net/core/skbuff.c:353 [inline] __alloc_skb+0x4dd/0xe90 net/core/skbuff.c:424 alloc_skb include/linux/skbuff.h:1103 [inline] alloc_skb_with_frags+0x1f3/0xc10 net/core/skbuff.c:5948 sock_alloc_send_pskb+0xdc1/0xf90 net/core/sock.c:2362 packet_alloc_skb net/packet/af_packet.c:2854 [inline] packet_snd net/packet/af_packet.c:2949 [inline] packet_sendmsg+0x6a12/0x99d0 net/packet/af_packet.c:3031 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg net/socket.c:674 [inline] ____sys_sendmsg+0xcfc/0x12f0 net/socket.c:2350 ___sys_sendmsg net/socket.c:2404 [inline] __sys_sendmsg+0x714/0x830 net/socket.c:2433 __compat_sys_sendmsg net/compat.c:347 [inline] __do_compat_sys_sendmsg net/compat.c:354 [inline] __se_compat_sys_sendmsg+0xa7/0xc0 net/compat.c:351 __ia32_compat_sys_sendmsg+0x4a/0x70 net/compat.c:351 do_syscall_32_irqs_on arch/x86/entry/common.c:79 [inline] __do_fast_syscall_32+0x127/0x180 arch/x86/entry/common.c:142 do_fast_syscall_32+0x77/0xd0 arch/x86/entry/common.c:168 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:211 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c =====================================================