Re: [PATCH v2 1/3] libceph: fix overflow in __decode_pool_names()

[Xi Wang <xi.wang@gmail.com>]

On Jun 6, 2012, at 12:26 PM, Alex Elder wrote:
>> diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
>> index 29ad46e..f80afc3 100644
>> --- a/net/ceph/osdmap.c
>> +++ b/net/ceph/osdmap.c
>> @@ -495,15 +495,12 @@ static int __decode_pool_names(void **p, void *end, struct ceph_osdmap *map)
>> 		ceph_decode_32_safe(p, end, pool, bad);
>> 		ceph_decode_32_safe(p, end, len, bad);
>> 		dout("  pool %d len %d\n", pool, len);
>> +		ceph_decode_need(p, end, len, bad);
>> 		pi = __lookup_pg_pool(&map->pg_pools, pool);
>> 		if (pi) {
>> 			kfree(pi->name);
>> -			pi->name = kmalloc(len + 1, GFP_NOFS);
>> -			if (pi->name) {
>> -				memcpy(pi->name, *p, len);
>> -				pi->name[len] = '\0';
>> -				dout("  name is %s\n", pi->name);
>> -			}
>> +			pi->name = kstrndup(*p, len, GFP_NOFS);
>> +			dout("  name is %s\n", pi->name);
> 
> Instead:
> 		if (pi) {
> 			char *name = kstrndup(*p, len, GFP_NOFS);
> 
> 			if (!name)
> 				return -ENOMEM;
> 			kfree(pi->name);
> 			pi->name = name;
> 			dout("  name is %s\n", pi->name);
> 		}

Looks good to me.  Thanks!

Do you want me to send another patch?

- xi