diff --git a/ChangeLog b/ChangeLog index 7c3e625c60..26dcfc715c 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2015-04-21 Arjun Shankar + + [BZ #18287] + * resolv/nss_dns/dns-host.c (getanswer_r): Adjust buffer length + based on padding. (CVE-2015-1781) + 2015-04-20 Adhemerval Zanella * nptl/pthread_cond_timedwait.c: Change include bits/libc-vdso.h to just diff --git a/NEWS b/NEWS index 2bbd6a3f8b..ccc4d135b9 100644 --- a/NEWS +++ b/NEWS @@ -16,7 +16,14 @@ Version 2.22 17969, 17978, 17987, 17991, 17996, 17998, 17999, 18019, 18020, 18029, 18030, 18032, 18036, 18038, 18039, 18042, 18043, 18046, 18047, 18068, 18080, 18093, 18100, 18104, 18110, 18111, 18128, 18138, 18185, 18197, - 18206, 18210, 18211, 18247. + 18206, 18210, 18211, 18247, 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) * A powerpc and powerpc64 optimization for TLS, similar to TLS descriptors for LD and GD on x86 and x86-64, has been implemented. You will need diff --git a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c index b16b0ddf11..d8c5579159 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: