git: 3e2308d57080 - stable/15 - rtnetlink: Check for allocation failure in nlattr_get_multipath()

The branch stable/15 has been updated by pouria:

URL: https://cgit.FreeBSD.org/src/commit/?id=3e2308d57080a2345e3db1139683368b504ee0bd

commit 3e2308d57080a2345e3db1139683368b504ee0bd
Author:     Pouria Mousavizadeh Tehrani <pouria@FreeBSD.org>
AuthorDate: 2026-05-11 19:53:21 +0000
Commit:     Pouria Mousavizadeh Tehrani <pouria@FreeBSD.org>
CommitDate: 2026-05-16 21:24:19 +0000

    rtnetlink: Check for allocation failure in nlattr_get_multipath()
    
    Check for alloction failure on `npt_alloc()` for RTA_MULTIPATH
    attributes in `nlattr_get_multipath()`.
    
    Reported by:    Joshua Rogers of AISLE Research Team
    Reviewed by:    markj
    MFC after:      3 days
    Differential Revision: https://reviews.freebsd.org/D56954
    
    (cherry picked from commit 188631e43a1a5d2985156141c2e244a925670683)
---
 sys/netlink/route/rt.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sys/netlink/route/rt.c b/sys/netlink/route/rt.c
index 7641417a8e77..a76e00d34502 100644
--- a/sys/netlink/route/rt.c
+++ b/sys/netlink/route/rt.c
@@ -447,6 +447,10 @@ nlattr_get_multipath(struct nlattr *nla, struct nl_pstate *npt,
 	max_nhops = data_len / sizeof(struct rtnexthop);
 
 	mp = npt_alloc(npt, (max_nhops + 2) * sizeof(struct rta_mpath_nh));
+	if (mp == NULL) {
+		NLMSG_REPORT_ERR_MSG(npt, "%s: too many RTA_MULTIPATH", __func__);
+		return (ENOMEM);
+	}
 	mp->num_nhops = 0;
 
 	for (rtnh = (struct rtnexthop *)(nla + 1); data_len > 0; ) {