3.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Xi Wang <xi.w...@gmail.com>
(cherry picked from commit e91a9b639a691e0982088b5954eaafb5a25c8f1c)
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.w...@gmail.com>
Reviewed-by: Alex Elder <el...@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
net/ceph/osdmap.c | 3 +++
1 file changed, 3 insertions(+)
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -674,6 +674,9 @@ struct ceph_osdmap *osdmap_decode(void *
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);
--
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