===================================================== BUG: KMSAN: uninit-value in ipv6_find_tlv+0x35d/0x3b0 net/ipv6/exthdrs_core.c:147 CPU: 1 PID: 11785 Comm: syz-executor.5 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 ipv6_find_tlv+0x35d/0x3b0 net/ipv6/exthdrs_core.c:147 ip6_find_1stfragopt+0x2a6/0x500 net/ipv6/output_core.c:102 ip6_fragment+0x2b2/0x3950 net/ipv6/ip6_output.c:776 __ip6_finish_output+0x73a/0x8e0 net/ipv6/ip6_output.c:140 ip6_finish_output+0x166/0x410 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x60a/0x770 net/ipv6/ip6_output.c:175 dst_output include/net/dst.h:436 [inline] ip6_local_out+0x164/0x1d0 net/ipv6/output_core.c:179 ip6_send_skb net/ipv6/ip6_output.c:1795 [inline] ip6_push_pending_frames+0x213/0x4f0 net/ipv6/ip6_output.c:1815 rawv6_push_pending_frames net/ipv6/raw.c:613 [inline] rawv6_sendmsg+0x4233/0x5c30 net/ipv6/raw.c:956 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_sendmsg+0x451/0x5f0 net/socket.c:2417 __do_sys_sendmsg net/socket.c:2426 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2424 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2424 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:00007fdb41c2cc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fdb41c2d6d4 RCX: 000000000045b349 RDX: 0000000000000000 RSI: 0000000020000a40 RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008d2 R14: 00000000004ca26a R15: 000000000075bf2c Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:82 slab_alloc_node mm/slub.c:2774 [inline] __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4382 __kmalloc_reserve net/core/skbuff.c:141 [inline] pskb_expand_head+0x20b/0x1b00 net/core/skbuff.c:1628 __pskb_pull_tail+0x17a/0x1dd0 net/core/skbuff.c:2059 pskb_may_pull include/linux/skbuff.h:2288 [inline] nf_ct_frag6_gather+0xf79/0x35f0 net/ipv6/netfilter/nf_conntrack_reasm.c:457 ipv6_defrag+0x523/0x640 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c:66 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline] nf_hook_slow+0x16e/0x400 net/netfilter/core.c:512 nf_hook include/linux/netfilter.h:262 [inline] __ip6_local_out+0x56d/0x750 net/ipv6/output_core.c:167 ip6_local_out+0xa4/0x1d0 net/ipv6/output_core.c:177 ip6_send_skb net/ipv6/ip6_output.c:1795 [inline] ip6_push_pending_frames+0x213/0x4f0 net/ipv6/ip6_output.c:1815 rawv6_push_pending_frames net/ipv6/raw.c:613 [inline] rawv6_sendmsg+0x4233/0x5c30 net/ipv6/raw.c:956 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_sendmsg+0x451/0x5f0 net/socket.c:2417 __do_sys_sendmsg net/socket.c:2426 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2424 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2424 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 =====================================================