From c836279fca80fb22ca7ef02acaa5b987fee61123 Mon Sep 17 00:00:00 2001 From: Yu Watanabe Date: Fri, 19 Oct 2018 03:42:10 +0900 Subject: [PATCH] sd-dhcp6: make dhcp6_option_parse_domainname() not store empty domain This improves performance of fuzzer. C.f. oss-fuzz#11019. (cherry picked from commit 3c72b6ed4252e7ff5f7704bfe44557ec197b47fa) (cherry picked from commit 50403cccee28c7dcd54b138a0d3b3f69ea0204fe) (cherry picked from commit f11f5abb1a8b96b553d2d156f8b5cf440695c04d) --- .../src/libsystemd-network/dhcp6-option.c | 56 ++++++++----------- 1 file changed, 24 insertions(+), 32 deletions(-) diff --git a/src/systemd/src/libsystemd-network/dhcp6-option.c b/src/systemd/src/libsystemd-network/dhcp6-option.c index cfddefcb56..be5c222372 100644 --- a/src/systemd/src/libsystemd-network/dhcp6-option.c +++ b/src/systemd/src/libsystemd-network/dhcp6-option.c @@ -555,6 +555,7 @@ int dhcp6_option_parse_domainname(const uint8_t *optval, uint16_t optlen, char * bool first = true; for (;;) { + const char *label; uint8_t c; c = optval[pos++]; @@ -562,47 +563,41 @@ int dhcp6_option_parse_domainname(const uint8_t *optval, uint16_t optlen, char * if (c == 0) /* End of name */ break; - else if (c <= 63) { - const char *label; + if (c > 63) + return -EBADMSG; - /* Literal label */ - label = (const char *)&optval[pos]; - pos += c; - if (pos >= optlen) - return -EMSGSIZE; + /* Literal label */ + label = (const char *)&optval[pos]; + pos += c; + if (pos >= optlen) + return -EMSGSIZE; - if (!GREEDY_REALLOC(ret, allocated, n + !first + DNS_LABEL_ESCAPED_MAX)) { - r = -ENOMEM; - goto fail; - } + if (!GREEDY_REALLOC(ret, allocated, n + !first + DNS_LABEL_ESCAPED_MAX)) + return -ENOMEM; - if (first) - first = false; - else - ret[n++] = '.'; + if (first) + first = false; + else + ret[n++] = '.'; - r = dns_label_escape(label, c, ret + n, DNS_LABEL_ESCAPED_MAX); - if (r < 0) - goto fail; + r = dns_label_escape(label, c, ret + n, DNS_LABEL_ESCAPED_MAX); + if (r < 0) + return r; - n += r; - continue; - } else { - r = -EBADMSG; - goto fail; - } + n += r; } - if (!GREEDY_REALLOC(ret, allocated, n + 1)) { - r = -ENOMEM; - goto fail; - } + if (n == 0) + continue; + + if (!GREEDY_REALLOC(ret, allocated, n + 1)) + return -ENOMEM; ret[n] = 0; r = strv_extend(&names, ret); if (r < 0) - goto fail; + return r; idx++; } @@ -610,7 +605,4 @@ int dhcp6_option_parse_domainname(const uint8_t *optval, uint16_t optlen, char * *str_arr = TAKE_PTR(names); return idx; - -fail: - return r; }