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[BZ #2499] 

* resolv/nss_dns/dns-canon.c (_nss_dns_getcanonname_r): Avoid
	possibly unaligned memory accesses.
This commit is contained in:
Ulrich Drepper 2006-05-06 19:18:15 +00:00
parent bce1646770
commit acb98cb57d
2 changed files with 13 additions and 7 deletions
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4
ChangeLog
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@ -1,5 +1,9 @@
2006-05-06 Ulrich Drepper <drepper@redhat.com> 2006-05-06 Ulrich Drepper <drepper@redhat.com>
[BZ #2499]
* resolv/nss_dns/dns-canon.c (_nss_dns_getcanonname_r): Avoid
possibly unaligned memory accesses.
* include/arpa/nameser.h: Also optimize NS_PUT16 and NS_PUT32. * include/arpa/nameser.h: Also optimize NS_PUT16 and NS_PUT32.
* resolv/res_mkquery.c: Use NS_PUT16 and NS_PUT32 instead of __putshort * resolv/res_mkquery.c: Use NS_PUT16 and NS_PUT32 instead of __putshort
and __putlong respectively. Correct buffer overflow check for and __putlong respectively. Correct buffer overflow check for

16
resolv/nss_dns/dns-canon.c
View File

@ -1,4 +1,4 @@
/* Copyright (C) 2004 Free Software Foundation, Inc. /* Copyright (C) 2004, 2006 Free Software Foundation, Inc.
This file is part of the GNU C Library. This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2004. Contributed by Ulrich Drepper <drepper@redhat.com>, 2004.
@ -40,6 +40,10 @@ typedef union querybuf
} querybuf; } querybuf;
static const short int qtypes[] = { ns_t_a, ns_t_aaaa };
#define nqtypes (sizeof (qtypes) / sizeof (qtypes[0]))
enum nss_status enum nss_status
_nss_dns_getcanonname_r (const char *name, char *buffer, size_t buflen, _nss_dns_getcanonname_r (const char *name, char *buffer, size_t buflen,
char **result,int *errnop, int *h_errnop) char **result,int *errnop, int *h_errnop)
@ -53,8 +57,6 @@ _nss_dns_getcanonname_r (const char *name, char *buffer, size_t buflen,
unsigned char *ptr; unsigned char *ptr;
} ansp = { .ptr = buf }; } ansp = { .ptr = buf };
enum nss_status status = NSS_STATUS_UNAVAIL; enum nss_status status = NSS_STATUS_UNAVAIL;
int qtypes[] = { ns_t_a, ns_t_aaaa };
#define nqtypes (sizeof (qtypes) / sizeof (qtypes[0]))
for (int i = 0; i < nqtypes; ++i) for (int i = 0; i < nqtypes; ++i)
{ {
@ -101,7 +103,8 @@ _nss_dns_getcanonname_r (const char *name, char *buffer, size_t buflen,
ptr += s; ptr += s;
/* Check whether type and class match. */ /* Check whether type and class match. */
unsigned int type = ntohs (*(uint16_t *) ptr); uint_fast16_t type;
NS_GET16 (type, ptr);
if (type == qtypes[i]) if (type == qtypes[i])
{ {
/* We found the record. */ /* We found the record. */
@ -130,15 +133,14 @@ _nss_dns_getcanonname_r (const char *name, char *buffer, size_t buflen,
if (type != ns_t_cname) if (type != ns_t_cname)
goto unavail; goto unavail;
ptr += sizeof (uint16_t); if (ns_get16 (ptr) != ns_c_in)
if (*(uint16_t *) ptr != htons (ns_c_in))
goto unavail; goto unavail;
/* Also skip over the TTL. */ /* Also skip over the TTL. */
ptr += sizeof (uint16_t) + sizeof (uint32_t); ptr += sizeof (uint16_t) + sizeof (uint32_t);
/* Skip over the data length and data. */ /* Skip over the data length and data. */
ptr += sizeof (uint16_t) + ntohs (*(uint16_t *) ptr); ptr += sizeof (uint16_t) + ns_get16 (ptr);
} }
} }
} }