From fbe0048b51d62f0c44e6e2b7267c29b66ba59912 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Tue, 17 Dec 2013 00:38:39 +0100 Subject: [PATCH] net: inet_diag: zero out uninitialized idiag_{src,dst} fields [ Upstream commit b1aac815c0891fe4a55a6b0b715910142227700f ] Jakub reported while working with nlmon netlink sniffer that parts of the inet_diag_sockid are not initialized when r->idiag_family != AF_INET6. That is, fields of r->id.idiag_src[1 ... 3], r->id.idiag_dst[1 ... 3]. In fact, it seems that we can leak 6 * sizeof(u32) byte of kernel [slab] memory through this. At least, in udp_dump_one(), we allocate a skb in ... rep = nlmsg_new(sizeof(struct inet_diag_msg) + ..., GFP_KERNEL); ... and then pass that to inet_sk_diag_fill() that puts the whole struct inet_diag_msg into the skb, where we only fill out r->id.idiag_src[0], r->id.idiag_dst[0] and leave the rest untouched: r->id.idiag_src[0] = inet->inet_rcv_saddr; r->id.idiag_dst[0] = inet->inet_daddr; struct inet_diag_msg embeds struct inet_diag_sockid that is correctly / fully filled out in IPv6 case, but for IPv4 not. So just zero them out by using plain memset (for this little amount of bytes it's probably not worth the extra check for idiag_family == AF_INET). Similarly, fix also other places where we fill that out. Reported-by: Jakub Zawadzki Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/inet_diag.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index 5f64875..31cf54d 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -106,6 +106,10 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk, r->id.idiag_sport = inet->inet_sport; r->id.idiag_dport = inet->inet_dport; + + memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src)); + memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst)); + r->id.idiag_src[0] = inet->inet_rcv_saddr; r->id.idiag_dst[0] = inet->inet_daddr; @@ -240,12 +244,19 @@ static int inet_twsk_diag_fill(struct inet_timewait_sock *tw, r->idiag_family = tw->tw_family; r->idiag_retrans = 0; + r->id.idiag_if = tw->tw_bound_dev_if; sock_diag_save_cookie(tw, r->id.idiag_cookie); + r->id.idiag_sport = tw->tw_sport; r->id.idiag_dport = tw->tw_dport; + + memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src)); + memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst)); + r->id.idiag_src[0] = tw->tw_rcv_saddr; r->id.idiag_dst[0] = tw->tw_daddr; + r->idiag_state = tw->tw_substate; r->idiag_timer = 3; r->idiag_expires = DIV_ROUND_UP(tmo * 1000, HZ); @@ -732,8 +743,13 @@ static int inet_diag_fill_req(struct sk_buff *skb, struct sock *sk, r->id.idiag_sport = inet->inet_sport; r->id.idiag_dport = ireq->rmt_port; + + memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src)); + memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst)); + r->id.idiag_src[0] = ireq->loc_addr; r->id.idiag_dst[0] = ireq->rmt_addr; + r->idiag_expires = jiffies_to_msecs(tmo); r->idiag_rqueue = 0; r->idiag_wqueue = 0; -- 2.7.4