From e91a9b639a691e0982088b5954eaafb5a25c8f1c 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 osdmap_decode() On 32-bit systems, a large `n' would overflow `n * sizeof(u32)' and bypass the check ceph_decode_need(p, end, n * sizeof(u32), bad). It would also overflow the subsequent kmalloc() size, leading to out-of-bounds write. Signed-off-by: Xi Wang Reviewed-by: Alex Elder --- net/ceph/osdmap.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c index df47871b8389..d70aaca4a45d 100644 --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -667,6 +667,9 @@ struct ceph_osdmap *osdmap_decode(void **p, void *end) ceph_decode_need(p, end, sizeof(u32) + sizeof(u64), bad); ceph_decode_copy(p, &pgid, sizeof(pgid)); n = ceph_decode_32(p); + err = -EINVAL; + if (n > (UINT_MAX - sizeof(*pg)) / sizeof(u32)) + goto bad; ceph_decode_need(p, end, n * sizeof(u32), bad); err = -ENOMEM; pg = kmalloc(sizeof(*pg) + n*sizeof(u32), GFP_NOFS); -- 2.39.5