Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Xi Wang , Alex Elder Subject: [ 113/171] libceph: fix overflow in osdmap_apply_incremental() Date: Wed, 21 Nov 2012 16:40:59 -0800 Message-Id: <20121122004044.694499787@linuxfoundation.org> In-Reply-To: <20121122004033.298367941@linuxfoundation.org> References: <20121122004033.298367941@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xi Wang (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 Reviewed-by: Alex Elder Signed-off-by: Greg Kroah-Hartman --- 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;