Patchwork [094/270] libceph: fix overflow in osdmap_apply_incremental()

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Submitter Herton Ronaldo Krzesinski
Date Nov. 26, 2012, 4:56 p.m.
Message ID <1353949160-26803-95-git-send-email-herton.krzesinski@canonical.com>
Download mbox | patch
Permalink /patch/201827/
State New
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Comments

Herton Ronaldo Krzesinski - Nov. 26, 2012, 4:56 p.m.
3.5.7u1 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Xi Wang <xi.wang@gmail.com>

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@gmail.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
---
 net/ceph/osdmap.c |    4 ++++
 1 file changed, 4 insertions(+)

Patch

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;