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Subject[ 113/171] libceph: fix overflow in osdmap_apply_incremental()
Date
3.4-stable review patch.  If anyone has any objections, please let me know.

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

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

(cherry picked from commit a5506049500b30dbc5edb4d07a3577477c1f3643)

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ceph/osdmap.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -900,6 +900,10 @@ struct ceph_osdmap *osdmap_apply_increme
(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;



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