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Incorrect Calculation of Buffer Size The advisory has been revoked - it doesn't affect any version of package rv  (opens in a new tab)

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  • Snyk IDSNYK-CENTOS10-RV-16190551
  • published24 Apr 2026
  • disclosed23 Apr 2026
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Introduced: 23 Apr 2026

CVE-2026-31531  (opens in a new tab)
CWE-131  (opens in a new tab)

Amendment

The Centos security team deemed this advisory irrelevant for Centos:10.

NVD Description

Note: Versions mentioned in the description apply only to the upstream rv package and not the rv package as distributed by Centos.

In the Linux kernel, the following vulnerability has been resolved:

ipv4: nexthop: allocate skb dynamically in rtm_get_nexthop()

When querying a nexthop object via RTM_GETNEXTHOP, the kernel currently allocates a fixed-size skb using NLMSG_GOODSIZE. While sufficient for single nexthops and small Equal-Cost Multi-Path groups, this fixed allocation fails for large nexthop groups like 512 nexthops.

This results in the following warning splat:

WARNING: net/ipv4/nexthop.c:3395 at rtm_get_nexthop+0x176/0x1c0, CPU#20: rep/4608 [...] RIP: 0010:rtm_get_nexthop (net/ipv4/nexthop.c:3395) [...] Call Trace: <TASK> rtnetlink_rcv_msg (net/core/rtnetlink.c:6989) netlink_rcv_skb (net/netlink/af_netlink.c:2550) netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344) netlink_sendmsg (net/netlink/af_netlink.c:1894) ____sys_sendmsg (net/socket.c:721 net/socket.c:736 net/socket.c:2585) ___sys_sendmsg (net/socket.c:2641) __sys_sendmsg (net/socket.c:2671) do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) </TASK>

Fix this by allocating the size dynamically using nh_nlmsg_size() and using nlmsg_new(), this is consistent with nexthop_notify() behavior. In addition, adjust nh_nlmsg_size_grp() so it calculates the size needed based on flags passed. While at it, also add the size of NHA_FDB for nexthop group size calculation as it was missing too.

This cannot be reproduced via iproute2 as the group size is currently limited and the command fails as follows:

addattr_l ERROR: message exceeded bound of 1048