From patchwork Mon Nov 26 16:56:24 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [094/270] libceph: fix overflow in osdmap_apply_incremental() Date: Mon, 26 Nov 2012 06:56:24 -0000 From: Herton Ronaldo Krzesinski X-Patchwork-Id: 201827 Message-Id: <1353949160-26803-95-git-send-email-herton.krzesinski@canonical.com> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Xi Wang 3.5.7u1 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Xi Wang 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 Reviewed-by: Alex Elder Signed-off-by: Herton Ronaldo Krzesinski --- 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;