From ad3b904c07dfa88603689bf9a67bffbb9b99beb5 Mon Sep 17 00:00:00 2001
From: Xi Wang <xi.wang@gmail.com>
Date: Wed, 6 Jun 2012 19:35:55 -0500
Subject: libceph: fix overflow in __decode_pool_names()
`len' is read from network and thus needs validation. Otherwise a
large `len' would cause out-of-bounds access via the memcpy() call.
In addition, len = 0xffffffff would overflow the kmalloc() size,
leading to out-of-bounds write.
This patch adds a check of `len' via ceph_decode_need(). Also use
kstrndup rather than kmalloc/memcpy.
[elder@inktank.com: added -ENOMEM return for null kstrndup() result]
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Reviewed-by: Alex Elder <elder@inktank.com>
---
net/ceph/osdmap.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
(limited to 'net/ceph')
diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
index 1892c523c43c..df47871b8389 100644
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -488,15 +488,16 @@ 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) {
+ char *name = kstrndup(*p, len, GFP_NOFS);
+
+ if (!name)
+ return -ENOMEM;
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 = name;
+ dout(" name is %s\n", pi->name);
}
*p += len;
}
--
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