diff options
| author | Andreas Schwab <schwab@suse.de> | 2014-02-13 11:01:57 +0100 |
|---|---|---|
| committer | Andreas Schwab <schwab@suse.de> | 2014-02-13 12:54:34 +0100 |
| commit | d668061994a7486a3ba9c7d5e7882d85a2883707 (patch) | |
| tree | ab372c220adff0fb3459d822e316f79917d9e803 /resolv | |
| parent | 743151aeaedc113900805523195fc3d9cff0bdb6 (diff) | |
Fix memory leak in _nss_dns_gethostbyname4_r with big DNS answer
Diffstat (limited to 'resolv')
| -rw-r--r-- | resolv/nss_dns/dns-host.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c index 541c25a348..365de7095f 100644 --- a/resolv/nss_dns/dns-host.c +++ b/resolv/nss_dns/dns-host.c @@ -298,13 +298,14 @@ _nss_dns_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat, name = cp; } + int anslen = 2048; union { querybuf *buf; u_char *ptr; } host_buffer; querybuf *orig_host_buffer; - host_buffer.buf = orig_host_buffer = (querybuf *) alloca (2048); + host_buffer.buf = orig_host_buffer = (querybuf *) alloca (anslen); u_char *ans2p = NULL; int nans2p = 0; int resplen2 = 0; @@ -312,7 +313,7 @@ _nss_dns_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat, int olderr = errno; enum nss_status status; int n = __libc_res_nsearch (&_res, name, C_IN, T_UNSPEC, - host_buffer.buf->buf, 2048, &host_buffer.ptr, + host_buffer.buf->buf, anslen, &host_buffer.ptr, &ans2p, &nans2p, &resplen2); if (n < 0) { @@ -352,6 +353,13 @@ _nss_dns_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat, resplen2, name, pat, buffer, buflen, errnop, herrnop, ttlp); + /* Check whether ans2p was separately allocated. */ + if (host_buffer.buf != orig_host_buffer) + anslen = MAXPACKET; + if (ans2p != NULL + && (ans2p < host_buffer.ptr || ans2p >= host_buffer.ptr + anslen)) + free (ans2p); + if (host_buffer.buf != orig_host_buffer) free (host_buffer.buf); |