diff options
| author | Eric Dumazet <edumazet@google.com> | 2018-04-29 09:54:59 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-05-01 12:15:24 -0400 |
| commit | cea67a2dd6b2419dcc13a39309b9a79a1f773193 (patch) | |
| tree | b43939d1051ed748e26cd493f2c044f8b9b7377f | |
| parent | f944ad1b2b66bbec8ffc1d6d0a45565b12846308 (diff) | |
ipv6: fix uninit-value in ip6_multipath_l3_keys()
syzbot/KMSAN reported an uninit-value in ip6_multipath_l3_keys(),
root caused to a bad assumption of ICMP header being already
pulled in skb->head
ip_multipath_l3_keys() does the correct thing, so it is an IPv6 only bug.
BUG: KMSAN: uninit-value in ip6_multipath_l3_keys net/ipv6/route.c:1830 [inline]
BUG: KMSAN: uninit-value in rt6_multipath_hash+0x5c4/0x640 net/ipv6/route.c:1858
CPU: 0 PID: 4507 Comm: syz-executor661 Not tainted 4.16.0+ #87
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x185/0x1d0 lib/dump_stack.c:53
kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
__msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683
ip6_multipath_l3_keys net/ipv6/route.c:1830 [inline]
rt6_multipath_hash+0x5c4/0x640 net/ipv6/route.c:1858
ip6_route_input+0x65a/0x920 net/ipv6/route.c:1884
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:4562
__netif_receive_skb net/core/dev.c:4627 [inline]
netif_receive_skb_internal+0x49d/0x630 net/core/dev.c:4701
netif_receive_skb+0x230/0x240 net/core/dev.c:4725
tun_rx_batched drivers/net/tun.c:1555 [inline]
tun_get_user+0x740f/0x7c60 drivers/net/tun.c:1962
tun_chr_write_iter+0x1d4/0x330 drivers/net/tun.c:1990
call_write_iter include/linux/fs.h:1782 [inline]
new_sync_write fs/read_write.c:469 [inline]
__vfs_write+0x7fb/0x9f0 fs/read_write.c:482
vfs_write+0x463/0x8d0 fs/read_write.c:544
SYSC_write+0x172/0x360 fs/read_write.c:589
SyS_write+0x55/0x80 fs/read_write.c:581
do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
Fixes: 23aebdacb05d ("ipv6: Compute multipath hash for ICMP errors from offending packet")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Jakub Sitnicki <jkbs@redhat.com>
Acked-by: Jakub Sitnicki <jkbs@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv6/route.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index cde7d8251377..f4d61736c41a 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1835,11 +1835,16 @@ static void ip6_multipath_l3_keys(const struct sk_buff *skb, const struct ipv6hdr *inner_iph; const struct icmp6hdr *icmph; struct ipv6hdr _inner_iph; + struct icmp6hdr _icmph; if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6)) goto out; - icmph = icmp6_hdr(skb); + icmph = skb_header_pointer(skb, skb_transport_offset(skb), + sizeof(_icmph), &_icmph); + if (!icmph) + goto out; + if (icmph->icmp6_type != ICMPV6_DEST_UNREACH && icmph->icmp6_type != ICMPV6_PKT_TOOBIG && icmph->icmp6_type != ICMPV6_TIME_EXCEED && |