diff options
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | NEWS | 9 | ||||
| -rw-r--r-- | resolv/nss_dns/dns-host.c | 3 |
3 files changed, 16 insertions, 2 deletions
diff --git a/ChangeLog b/ChangeLog index 45579dea40..26feb0734e 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2015-04-21 Arjun Shankar <arjun.is@lostca.se> + + [BZ #18287] + * resolv/nss_dns/dns-host.c (getanswer_r): Adjust buffer length + based on padding. (CVE-2015-1781) + 2015-02-10 Evangelos Foutras <evangelos@foutrelis.com> [BZ #17949] diff --git a/NEWS b/NEWS index ff79f0d1b5..c9f6b58486 100644 --- a/NEWS +++ b/NEWS @@ -9,7 +9,14 @@ Version 2.21.1 * The following bugs are resolved with this release: - 17949. + 17949, 18287. + +* A buffer overflow in gethostbyname_r and related functions performing DNS + requests has been fixed. If the NSS functions were called with a + misaligned buffer, the buffer length change due to pointer alignment was + not taken into account. This could result in application crashes or, + potentially arbitrary code execution, using crafted, but syntactically + valid DNS responses. (CVE-2015-1781) Version 2.21 diff --git a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c index f715ab0b3f..40069a73c6 100644 --- a/resolv/nss_dns/dns-host.c +++ b/resolv/nss_dns/dns-host.c @@ -615,7 +615,8 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype, int have_to_map = 0; uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct host_data); buffer += pad; - if (__glibc_unlikely (buflen < sizeof (struct host_data) + pad)) + buflen = buflen > pad ? buflen - pad : 0; + if (__glibc_unlikely (buflen < sizeof (struct host_data))) { /* The buffer is too small. */ too_small: |