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gluon-radv-filterd: Check for recvfrom errors

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The recvfrom can fail and return -1. The caller must check for this error
to avoid that it reads uninitialized data from pkt.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
This commit is contained in:
Sven Eckelmann 2017-12-20 12:29:24 +01:00 committed by Jan-Philipp Litza
parent 3c8b9fd281
commit 1633c7c005
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GPG Key ID: 1FB658053CE27196
1 changed files with 3 additions and 2 deletions
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package/gluon-radv-filterd/src/gluon-radv-filterd.c
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@ -319,16 +319,17 @@ static void handle_ra(int sock) {
struct sockaddr_ll src;
struct ether_addr mac;
unsigned int addr_size = sizeof(src);
size_t len;
ssize_t len;
struct {
struct ip6_hdr ip6;
struct nd_router_advert ra;
} pkt;
len = recvfrom(sock, &pkt, sizeof(pkt), 0, (struct sockaddr *)&src, &addr_size);
CHECK(len >= 0);
// BPF already checked that this is an ICMPv6 RA of a default router
CHECK(len >= sizeof(pkt));
CHECK((size_t)len >= sizeof(pkt));
CHECK(ntohs(pkt.ip6.ip6_plen) + sizeof(struct ip6_hdr) >= sizeof(pkt));
memcpy(&mac, src.sll_addr, sizeof(mac));