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lib/vsprintf.c: Avoid possible unaligned accesses in %pI6c

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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>
This commit is contained in:
Joe Perches 2009-09-18 13:04:06 +00:00 committed by David S. Miller
parent 95acf7d7ed
commit eb78cd26b9
1 changed files with 15 additions and 10 deletions
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25
lib/vsprintf.c
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@ -671,7 +671,7 @@ static char *ip4_string(char *p, const u8 *addr, bool leading_zeros)
return p; 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 i;
int j; int j;
@ -683,7 +683,12 @@ static char *ip6_compressed_string(char *p, const struct in6_addr *addr)
u8 hi; u8 hi;
u8 lo; u8 lo;
bool needcolon = false; 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)); memset(zerolength, 0, sizeof(zerolength));
@ -695,7 +700,7 @@ static char *ip6_compressed_string(char *p, const struct in6_addr *addr)
/* find position of longest 0 run */ /* find position of longest 0 run */
for (i = 0; i < range; i++) { for (i = 0; i < range; i++) {
for (j = i; j < range; j++) { for (j = i; j < range; j++) {
if (addr->s6_addr16[j] != 0) if (in6.s6_addr16[j] != 0)
break; break;
zerolength[i]++; zerolength[i]++;
} }
@ -722,7 +727,7 @@ static char *ip6_compressed_string(char *p, const struct in6_addr *addr)
needcolon = false; needcolon = false;
} }
/* hex u16 without leading 0s */ /* hex u16 without leading 0s */
word = ntohs(addr->s6_addr16[i]); word = ntohs(in6.s6_addr16[i]);
hi = word >> 8; hi = word >> 8;
lo = word & 0xff; lo = word & 0xff;
if (hi) { if (hi) {
@ -741,19 +746,19 @@ static char *ip6_compressed_string(char *p, const struct in6_addr *addr)
if (useIPv4) { if (useIPv4) {
if (needcolon) if (needcolon)
*p++ = ':'; *p++ = ':';
p = ip4_string(p, &addr->s6_addr[12], false); p = ip4_string(p, &in6.s6_addr[12], false);
} }
*p = '\0'; *p = '\0';
return p; 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; int i;
for (i = 0; i < 8; i++) { for (i = 0; i < 8; i++) {
p = pack_hex_byte(p, addr->s6_addr[2 * i]); p = pack_hex_byte(p, *addr++);
p = pack_hex_byte(p, addr->s6_addr[2 * i + 1]); p = pack_hex_byte(p, *addr++);
if (fmt[0] == 'I' && i != 7) if (fmt[0] == 'I' && i != 7)
*p++ = ':'; *p++ = ':';
} }
@ -768,9 +773,9 @@ static char *ip6_addr_string(char *buf, char *end, const u8 *addr,
char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")]; char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
if (fmt[0] == 'I' && fmt[2] == 'c') if (fmt[0] == 'I' && fmt[2] == 'c')
ip6_compressed_string(ip6_addr, (const struct in6_addr *)addr); ip6_compressed_string(ip6_addr, addr);
else else
ip6_string(ip6_addr, (const struct in6_addr *)addr, fmt); ip6_string(ip6_addr, addr, fmt);
return string(buf, end, ip6_addr, spec); return string(buf, end, ip6_addr, spec);
} }