From b37da3ac099e145bcd3be82c745a8d335772e3af Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Tue, 2 Jun 2026 15:50:14 +0800 Subject: [PATCH] net: mctp: ensure our nlmsg responses are initialised [ Upstream commit a6a9bc544b675d8b5180f2718ec985ad267b5cbf ] Syed Faraz Abrar (@farazsth98) from Zellic, and Pumpkin (@u1f383) from DEVCORE Research Team working with Trend Micro Zero Day Initiative report that a RTM_GETNEIGH will return uninitalised data in the pad bytes of the ndmsg data. Ensure we're initialising the netlink data to zero, in the link, addr and neigh response messages. Fixes: 831119f88781 ("mctp: Add neighbour netlink interface") Fixes: 06d2f4c583a7 ("mctp: Add netlink route management") Fixes: 583be982d934 ("mctp: Add device handling and netlink interface") Signed-off-by: Jeremy Kerr Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260209-dev-mctp-nlmsg-v1-1-f1e30c346a43@codeconstruct.com.au Signed-off-by: Jakub Kicinski Signed-off-by: Li hongliang <1468888505@139.com> Signed-off-by: Sasha Levin --- net/mctp/device.c | 1 + net/mctp/neigh.c | 1 + net/mctp/route.c | 1 + 3 files changed, 3 insertions(+) diff --git a/net/mctp/device.c b/net/mctp/device.c index aec7ffad2666..a11d5aca201c 100644 --- a/net/mctp/device.c +++ b/net/mctp/device.c @@ -55,6 +55,7 @@ static int mctp_fill_addrinfo(struct sk_buff *skb, struct netlink_callback *cb, return -EMSGSIZE; hdr = nlmsg_data(nlh); + memset(hdr, 0, sizeof(*hdr)); hdr->ifa_family = AF_MCTP; hdr->ifa_prefixlen = 0; hdr->ifa_flags = 0; diff --git a/net/mctp/neigh.c b/net/mctp/neigh.c index bc75a263719c..18a6be38f172 100644 --- a/net/mctp/neigh.c +++ b/net/mctp/neigh.c @@ -217,6 +217,7 @@ static int mctp_fill_neigh(struct sk_buff *skb, u32 portid, u32 seq, int event, return -EMSGSIZE; hdr = nlmsg_data(nlh); + memset(hdr, 0, sizeof(*hdr)); hdr->ndm_family = AF_MCTP; hdr->ndm_ifindex = dev->ifindex; hdr->ndm_state = 0; // TODO other state bits? diff --git a/net/mctp/route.c b/net/mctp/route.c index 48d32bfd3863..a93796eb0a09 100644 --- a/net/mctp/route.c +++ b/net/mctp/route.c @@ -1031,6 +1031,7 @@ static int mctp_fill_rtinfo(struct sk_buff *skb, struct mctp_route *rt, return -EMSGSIZE; hdr = nlmsg_data(nlh); + memset(hdr, 0, sizeof(*hdr)); hdr->rtm_family = AF_MCTP; /* we use the _len fields as a number of EIDs, rather than