From f4d29a959aa619f3d46e2b685cfb8acac41503db Mon Sep 17 00:00:00 2001 From: Xi Wang Date: Wed, 6 Jun 2012 19:35:55 -0500 Subject: [PATCH] libceph: fix overflow in osdmap_apply_incremental() (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(+) diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c index a38ce3f..c771334 100644 --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -900,6 +900,10 @@ 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; -- 2.7.4