Commit 2334e973 authored by YOSHIFUJI Hideaki's avatar YOSHIFUJI Hideaki Committed by David S. Miller
Browse files

[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: default avatarYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
parent 9e412ba7

include/net/ipv6.h

+1 −1
Original line number Diff line number Diff line
@@ -172,7 +172,7 @@ int snmp6_alloc_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);

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

{

net/ipv6/proc.c

+16 −6
Original line number Diff line number Diff line
@@ -210,20 +210,30 @@ static const struct file_operations snmp6_seq_fops = { 
};

#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

__snmp6_fill_stats(u64 *stats, void **mib, int items, int bytes)

__snmp6_fill_stats(void *stats, void **mib, int items, int bytes)

{

	int i;

	u8 *p = stats;

	int pad = bytes - sizeof(u64) * items;

	BUG_ON(pad < 0);

	stats[0] = items;

	for (i = 1; i < items; i++)

		stats[i] = (u64)fold_field(mib, i);

	memset(&stats[items], 0, pad);

	__set_u64(p, items);

	for (i = 1, p += sizeof(u64); i < items; i++, p += sizeof(u64))

		__set_u64(p, fold_field(mib, i));

	memset(p, 0, pad);

}



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) {

	case IFLA_INET6_STATS: