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[IPV6] SNMP: Avoid unaligned accesses. 

Because stats pointer may not be aligned for u64, use memcpy
to fill u64 values.
Issue reported by David Miller <davem@davemloft.net>.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
This commit is contained in:
YOSHIFUJI Hideaki 2007-04-21 20:12:43 +09:00 committed by David S. Miller
parent 9e412ba763
commit 2334e97355
2 changed files with 17 additions and 7 deletions
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2
include/net/ipv6.h
View File

@ -172,7 +172,7 @@ int snmp6_alloc_dev(struct inet6_dev *idev);
int snmp6_free_dev(struct inet6_dev *idev); int snmp6_free_dev(struct inet6_dev *idev);
int snmp6_mib_init(void *ptr[2], size_t mibsize, size_t mibalign); int snmp6_mib_init(void *ptr[2], size_t mibsize, size_t mibalign);
void snmp6_mib_free(void *ptr[2]); void snmp6_mib_free(void *ptr[2]);
void snmp6_fill_stats(u64 *stats, struct inet6_dev *idev, int attrtype, int bytes); void snmp6_fill_stats(void *stats, struct inet6_dev *idev, int attrtype, int bytes);
struct ip6_ra_chain struct ip6_ra_chain
{ {

22
net/ipv6/proc.c
View File

@ -210,20 +210,30 @@ static const struct file_operations snmp6_seq_fops = {
}; };
#endif /* CONFIG_PROC_FS */ #endif /* CONFIG_PROC_FS */
/*
* Stats may not be aligned for u64, so use memcpy to avoid
* unaligned accesses.
*/
static inline void __set_u64(void *p, u64 v)
{
memcpy(p, &v, sizeof(u64));
}
static inline void static inline void
__snmp6_fill_stats(u64 *stats, void **mib, int items, int bytes) __snmp6_fill_stats(void *stats, void **mib, int items, int bytes)
{ {
int i; int i;
u8 *p = stats;
int pad = bytes - sizeof(u64) * items; int pad = bytes - sizeof(u64) * items;
BUG_ON(pad < 0); BUG_ON(pad < 0);
stats[0] = items; __set_u64(p, items);
for (i = 1; i < items; i++) for (i = 1, p += sizeof(u64); i < items; i++, p += sizeof(u64))
stats[i] = (u64)fold_field(mib, i); __set_u64(p, fold_field(mib, i));
memset(&stats[items], 0, pad); memset(p, 0, pad);
} }
void void
snmp6_fill_stats(u64 *stats, struct inet6_dev *idev, int attrtype, int bytes) snmp6_fill_stats(void *stats, struct inet6_dev *idev, int attrtype, int bytes)
{ {
switch(attrtype) { switch(attrtype) {
case IFLA_INET6_STATS: case IFLA_INET6_STATS: