diff options
| author | Xi Wang <xi.wang@gmail.com> | 2012-06-06 19:35:55 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-11-26 11:38:24 -0800 |
| commit | c66a9c7c10955499d96df63ffd87feaee6b01754 (patch) | |
| tree | 4276bd716521f0a4c14ed641aab6d2700309bf2c | |
| parent | ce4516fbb42d2ad5adba4699ebc1703d4e08e821 (diff) | |
| download | lwn-c66a9c7c10955499d96df63ffd87feaee6b01754.tar.gz lwn-c66a9c7c10955499d96df63ffd87feaee6b01754.zip | |
libceph: fix overflow in __decode_pool_names()
(cherry picked from commit ad3b904c07dfa88603689bf9a67bffbb9b99beb5)
`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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/ceph/osdmap.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c index 7173ad54d239..77abb1315866 100644 --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -495,15 +495,16 @@ 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; } |