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| author |   Olivier Matz <olivier.matz@6wind.com> | 2019-06-06 09:15:19 +0200 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2019-06-06 10:29:21 -0700 |
| commit | b9aa52c4cb457e7416cc0c95f475e72ef4a61336 (patch) | |
| tree | 2dbe76f0f5c136bcb3c378d5e5c0a98dacdac774 /net/ipv6 | |
| parent | ipv6: use READ_ONCE() for inet->hdrincl as in ipv4 (diff) | |
| download | linux-dev-b9aa52c4cb457e7416cc0c95f475e72ef4a61336.tar.xz linux-dev-b9aa52c4cb457e7416cc0c95f475e72ef4a61336.zip | |
ipv6: fix EFAULT on sendto with icmpv6 and hdrincl
The following code returns EFAULT (Bad address):
s = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
setsockopt(s, SOL_IPV6, IPV6_HDRINCL, 1);
sendto(ipv6_icmp6_packet, addr); /* returns -1, errno = EFAULT */
The IPv4 equivalent code works. A workaround is to use IPPROTO_RAW
instead of IPPROTO_ICMPV6.
The failure happens because 2 bytes are eaten from the msghdr by
rawv6_probe_proto_opt() starting from commit 19e3c66b52ca ("ipv6
equivalent of "ipv4: Avoid reading user iov twice after
raw_probe_proto_opt""), but at that time it was not a problem because
IPV6_HDRINCL was not yet introduced.
Only eat these 2 bytes if hdrincl == 0.
Fixes: 715f504b1189 ("ipv6: add IPV6_HDRINCL option for raw sockets")
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/raw.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index af2f9a833c4e..1bb88b4b677b 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -895,11 +895,14 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) opt = ipv6_fixup_options(&opt_space, opt); fl6.flowi6_proto = proto; - rfv.msg = msg; - rfv.hlen = 0; - err = rawv6_probe_proto_opt(&rfv, &fl6); - if (err) - goto out; + + if (!hdrincl) { + rfv.msg = msg; + rfv.hlen = 0; + err = rawv6_probe_proto_opt(&rfv, &fl6); + if (err) + goto out; + } if (!ipv6_addr_any(daddr)) fl6.daddr = *daddr; |