On 32-bit systems, a large `n' would overflow `n * sizeof(u32)' and bypass the check ceph_decode_need(p, end, n * 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 | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c index f80afc3..774eac6 100644 --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -670,6 +670,9 @@ struct ceph_osdmap *osdmap_decode(void **p, void *end) ceph_decode_need(p, end, sizeof(u32) + sizeof(u64), bad); ceph_decode_copy(p, &pgid, sizeof(pgid)); n = ceph_decode_32(p); + err = -EINVAL; + if (n > (UINT_MAX - sizeof(*pg)) / sizeof(u32)) + goto bad; ceph_decode_need(p, end, n * sizeof(u32), bad); err = -ENOMEM; pg = kmalloc(sizeof(*pg) + n*sizeof(u32), GFP_NOFS); -- 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
