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

[Alex Elder <elder@inktank.com>]

On 06/06/2012 12:54 PM, Xi Wang wrote:
> 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?

Nope.  It's already done, I just wasn't going to commit it without
hearing back from you.

Thanks.

					-Alex