3.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Xi Wang <[email protected]> (cherry picked from commit e91a9b639a691e0982088b5954eaafb5a25c8f1c) 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]> Reviewed-by: Alex Elder <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- net/ceph/osdmap.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -674,6 +674,9 @@ struct ceph_osdmap *osdmap_decode(void * 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
