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 <[email protected]> --- net/ceph/osdmap.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c index 774eac6..b1ea6d1 100644 --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -891,6 +891,10 @@ struct ceph_osdmap *osdmap_apply_incremental(void **p, void *end, if (pglen) { /* insert */ + if (pglen > (UINT_MAX - sizeof(*pg)) / sizeof(u32)) { + err = -EINVAL; + goto bad; + } ceph_decode_need(p, end, pglen*sizeof(u32), bad); pg = kmalloc(sizeof(*pg) + sizeof(u32)*pglen, GFP_NOFS); if (!pg) { -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
