This condition doesn't work when len is smaller than expected and not a multiple of 4. In that situation "len - pos" is negative and type promoted to a high unsigned value and we do not break out of the loop. It causes the program calling it to crash.
Fixes: b42be38b2778 ('netlink: add API to retrieve all group memberships') Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com> diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 59651af..76a8466 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2373,7 +2373,7 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname, err = 0; netlink_lock_table(); for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) { - if (len - pos < sizeof(u32)) + if (len < pos + sizeof(u32)) break; idx = pos / sizeof(unsigned long); -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html