lib/vsprintf.c: Avoid possible unaligned accesses in %pI6c
Jens Rosenboom noticed that a possibly unaligned const char*
is cast to a const struct in6_addr *.
Avoid this at the cost of a struct in6_addr copy on the stack.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index cb8a112..a1941f8 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -671,7 +671,7 @@
return p;
}
-static char *ip6_compressed_string(char *p, const struct in6_addr *addr)
+static char *ip6_compressed_string(char *p, const char *addr)
{
int i;
int j;
@@ -683,7 +683,12 @@
u8 hi;
u8 lo;
bool needcolon = false;
- bool useIPv4 = ipv6_addr_v4mapped(addr) || ipv6_addr_is_isatap(addr);
+ bool useIPv4;
+ struct in6_addr in6;
+
+ memcpy(&in6, addr, sizeof(struct in6_addr));
+
+ useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
memset(zerolength, 0, sizeof(zerolength));
@@ -695,7 +700,7 @@
/* find position of longest 0 run */
for (i = 0; i < range; i++) {
for (j = i; j < range; j++) {
- if (addr->s6_addr16[j] != 0)
+ if (in6.s6_addr16[j] != 0)
break;
zerolength[i]++;
}
@@ -722,7 +727,7 @@
needcolon = false;
}
/* hex u16 without leading 0s */
- word = ntohs(addr->s6_addr16[i]);
+ word = ntohs(in6.s6_addr16[i]);
hi = word >> 8;
lo = word & 0xff;
if (hi) {
@@ -741,19 +746,19 @@
if (useIPv4) {
if (needcolon)
*p++ = ':';
- p = ip4_string(p, &addr->s6_addr[12], false);
+ p = ip4_string(p, &in6.s6_addr[12], false);
}
*p = '\0';
return p;
}
-static char *ip6_string(char *p, const struct in6_addr *addr, const char *fmt)
+static char *ip6_string(char *p, const char *addr, const char *fmt)
{
int i;
for (i = 0; i < 8; i++) {
- p = pack_hex_byte(p, addr->s6_addr[2 * i]);
- p = pack_hex_byte(p, addr->s6_addr[2 * i + 1]);
+ p = pack_hex_byte(p, *addr++);
+ p = pack_hex_byte(p, *addr++);
if (fmt[0] == 'I' && i != 7)
*p++ = ':';
}
@@ -768,9 +773,9 @@
char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
if (fmt[0] == 'I' && fmt[2] == 'c')
- ip6_compressed_string(ip6_addr, (const struct in6_addr *)addr);
+ ip6_compressed_string(ip6_addr, addr);
else
- ip6_string(ip6_addr, (const struct in6_addr *)addr, fmt);
+ ip6_string(ip6_addr, addr, fmt);
return string(buf, end, ip6_addr, spec);
}