From bfe9a589a402d4b6265e32b1b5ca0942efdcff3b Mon Sep 17 00:00:00 2001 From: Timo Teras Date: Fri, 7 May 2010 11:30:04 +0300 Subject: [PATCH 2/2] resolv: various memory corruption and off by one fixes Fixes resolution of names with AAAA entries and gethostbyaddr issues. Signed-off-by: Timo Teras --- libc/inet/resolv.c | 12 ++++++++---- 1 files changed, 8 insertions(+), 4 deletions(-) diff --git a/libc/inet/resolv.c b/libc/inet/resolv.c index 84289a6..320aec4 100644 --- a/libc/inet/resolv.c +++ b/libc/inet/resolv.c @@ -689,7 +689,7 @@ int attribute_hidden __decode_dotted(const unsigned char *packet, if (used + b + 1 >= dest_len) return -1; - if (offset + b + 1 >= packet_len) + if (offset + b >= packet_len) return -1; memcpy(dest + used, packet + offset, b); offset += b; @@ -2417,7 +2417,7 @@ int gethostbyaddr_r(const void *addr, socklen_t addrlen, /* Layout in buf: * char *alias[ALIAS_DIM]; * struct in[6]_addr* addr_list[2]; - * struct in[6]_addr* in; + * struct in[6]_addr in; * char scratch_buffer[256+]; */ #define in6 ((struct in6_addr *)in) @@ -2431,9 +2431,13 @@ int gethostbyaddr_r(const void *addr, socklen_t addrlen, #ifndef __UCLIBC_HAS_IPV6__ buf += sizeof(*in); buflen -= sizeof(*in); + if (addrlen > sizeof(*in)) + return ERANGE; #else buf += sizeof(*in6); buflen -= sizeof(*in6); + if (addrlen > sizeof(*in6)) + return ERANGE; #endif if ((ssize_t)buflen < 256) return ERANGE; @@ -2441,7 +2445,7 @@ int gethostbyaddr_r(const void *addr, socklen_t addrlen, alias[1] = NULL; addr_list[0] = in; addr_list[1] = NULL; - memcpy(&in, addr, addrlen); + memcpy(in, addr, addrlen); if (0) /* nothing */; #ifdef __UCLIBC_HAS_IPV4__ @@ -2456,7 +2460,7 @@ int gethostbyaddr_r(const void *addr, socklen_t addrlen, char *dst = buf; unsigned char *tp = (unsigned char *)addr + addrlen - 1; do { - dst += sprintf(dst, "%x.%x.", tp[i] & 0xf, tp[i] >> 4); + dst += sprintf(dst, "%x.%x.", tp[0] & 0xf, tp[0] >> 4); tp--; } while (tp >= (unsigned char *)addr); strcpy(dst, "ip6.arpa"); -- 1.6.3.3