From ad3b904c07dfa88603689bf9a67bffbb9b99beb5 Mon Sep 17 00:00:00 2001 From: Xi Wang Date: Wed, 6 Jun 2012 19:35:55 -0500 Subject: [PATCH] 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 Reviewed-by: Alex Elder --- net/ceph/osdmap.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) 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; } -- GitLab