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BUG: KMSAN: uninit-value in ip6_multipath_l3_keys net/ipv6/route.c:1843 [inline]
BUG: KMSAN: uninit-value in rt6_multipath_hash+0xbe8/0xc80 net/ipv6/route.c:1883
CPU: 0 PID: 12263 Comm: syz-executor7 Not tainted 4.17.0-rc3+ #93
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+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1084
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683
 ip6_multipath_l3_keys net/ipv6/route.c:1843 [inline]
 rt6_multipath_hash+0xbe8/0xc80 net/ipv6/route.c:1883
 ip6_route_input+0x858/0xb60 net/ipv6/route.c:1952
 ip6_rcv_finish+0x413/0x6e0 net/ipv6/ip6_input.c:69
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ipv6_rcv+0x1e16/0x2340 net/ipv6/ip6_input.c:208
 __netif_receive_skb_core+0x47df/0x4a90 net/core/dev.c:4592
 __netif_receive_skb net/core/dev.c:4657 [inline]
 netif_receive_skb_internal+0x49d/0x630 net/core/dev.c:4731
 netif_receive_skb+0x230/0x240 net/core/dev.c:4755
 tun_rx_batched drivers/net/tun.c:1558 [inline]
 tun_get_user+0x6b67/0x7e40 drivers/net/tun.c:1962
 tun_chr_write_iter+0x1d4/0x330 drivers/net/tun.c:1990
 call_write_iter include/linux/fs.h:1784 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x7fb/0x9f0 fs/read_write.c:487
 vfs_write+0x463/0x8d0 fs/read_write.c:549
 ksys_write fs/read_write.c:598 [inline]
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x1bf/0x3e0 fs/read_write.c:607
 do_syscall_64+0x154/0x220 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x455a09
RSP: 002b:00007f08feecac68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f08feecb6d4 RCX: 0000000000455a09
RDX: 0000000000000fca RSI: 0000000020000480 RDI: 0000000000000014
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000790 R14: 00000000006ff620 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:189
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:315
 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan.c:322
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2753 [inline]
 __kmalloc_node_track_caller+0xb32/0x11b0 mm/slub.c:4395
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x2cf/0x9f0 net/core/skbuff.c:206
 alloc_skb include/linux/skbuff.h:988 [inline]
 alloc_skb_with_frags+0x1e6/0xb80 net/core/skbuff.c:5254
 sock_alloc_send_pskb+0xb56/0x1190 net/core/sock.c:2088
 tun_alloc_skb drivers/net/tun.c:1535 [inline]
 tun_get_user+0x21d9/0x7e40 drivers/net/tun.c:1829
 tun_chr_write_iter+0x1d4/0x330 drivers/net/tun.c:1990
 call_write_iter include/linux/fs.h:1784 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x7fb/0x9f0 fs/read_write.c:487
 vfs_write+0x463/0x8d0 fs/read_write.c:549
 ksys_write fs/read_write.c:598 [inline]
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x1bf/0x3e0 fs/read_write.c:607
 do_syscall_64+0x154/0x220 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
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