[PATCH 094/270] libceph: fix overflow in osdmap_apply_incremental()
From: Herton Ronaldo Krzesinski
Date: Mon Nov 26 2012 - 13:01:29 EST
3.5.7u1 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Xi Wang <xi.wang@xxxxxxxxx>
commit a5506049500b30dbc5edb4d07a3577477c1f3643 upstream.
On 32-bit systems, a large `pglen' would overflow `pglen*sizeof(u32)'
and bypass the check ceph_decode_need(p, end, pglen*sizeof(u32), bad).
It would also overflow the subsequent kmalloc() size, leading to
out-of-bounds write.
Signed-off-by: Xi Wang <xi.wang@xxxxxxxxx>
Reviewed-by: Alex Elder <elder@xxxxxxxxxxx>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@xxxxxxxxxxxxx>
---
net/ceph/osdmap.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
index bc73341..9600674 100644
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -893,6 +893,10 @@ struct ceph_osdmap *osdmap_apply_incremental(void **p, void *end,
(void) __remove_pg_mapping(&map->pg_temp, pgid);
/* insert */
+ if (pglen > (UINT_MAX - sizeof(*pg)) / sizeof(u32)) {
+ err = -EINVAL;
+ goto bad;
+ }
pg = kmalloc(sizeof(*pg) + sizeof(u32)*pglen, GFP_NOFS);
if (!pg) {
err = -ENOMEM;
--
1.7.9.5
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