net: mctp: ensure our nlmsg responses are initialised

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: 831119f887 ("mctp: Add neighbour netlink interface")
Fixes: 06d2f4c583 ("mctp: Add netlink route management")
Fixes: 583be982d9 ("mctp: Add device handling and netlink interface")
Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260209-dev-mctp-nlmsg-v1-1-f1e30c346a43@codeconstruct.com.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
master
Jeremy Kerr 2026-02-09 15:27:33 +08:00 committed by Jakub Kicinski
parent 7c375811b5
commit a6a9bc544b
3 changed files with 3 additions and 0 deletions

View File

@ -70,6 +70,7 @@ static int mctp_fill_addrinfo(struct sk_buff *skb,
return -EMSGSIZE;
hdr = nlmsg_data(nlh);
memset(hdr, 0, sizeof(*hdr));
hdr->ifa_family = AF_MCTP;
hdr->ifa_prefixlen = 0;
hdr->ifa_flags = 0;

View File

@ -218,6 +218,7 @@ 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?

View File

@ -1643,6 +1643,7 @@ 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