path: root/net/ceph/osdmap.c
diff options
authorXi Wang <xi.wang@gmail.com>2012-06-06 19:35:55 -0500
committerAlex Elder <elder@dreamhost.com>2012-06-07 08:28:10 -0500
commite91a9b639a691e0982088b5954eaafb5a25c8f1c (patch)
tree3ffdd2430ba72fefa9d8fb7eef73625d395de01d /net/ceph/osdmap.c
parentad3b904c07dfa88603689bf9a67bffbb9b99beb5 (diff)
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 <xi.wang@gmail.com> Reviewed-by: Alex Elder <elder@inktank.com>
Diffstat (limited to 'net/ceph/osdmap.c')
1 files changed, 3 insertions, 0 deletions
diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
index df47871b838..d70aaca4a45 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);