CVE-2026-43501 Affecting kernel-macros package, versions <5.14.21-150400.24.222.1


Severity

Recommended
0.0
high
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.4% (32nd percentile)

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  • Snyk IDSNYK-SLES154-KERNELMACROS-17333574
  • published13 Jun 2026
  • disclosed12 Jun 2026

Introduced: 12 Jun 2026

NewCVE-2026-43501  (opens in a new tab)

How to fix?

Upgrade SLES:15.4 kernel-macros to version 5.14.21-150400.24.222.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-macros package and not the kernel-macros package as distributed by SLES. See How to fix? for SLES:15.4 relevant fixed versions and status.

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

ipv6: rpl: reserve mac_len headroom when recompressed SRH grows

ipv6_rpl_srh_rcv() decompresses an RFC 6554 Source Routing Header, swaps the next segment into ipv6_hdr->daddr, recompresses, then pulls the old header and pushes the new one plus the IPv6 header back. The recompressed header can be larger than the received one when the swap reduces the common-prefix length the segments share with daddr (CmprI=0, CmprE>0, seg[0][0] != daddr[0] gives the maximum +8 bytes).

pskb_expand_head() was gated on segments_left == 0, so on earlier segments the push consumed unchecked headroom. Once skb_push() leaves fewer than skb->mac_len bytes in front of data, skb_mac_header_rebuild()'s call to:

skb_set_mac_header(skb, -skb-&gt;mac_len);

will store (data - head) - mac_len into the u16 mac_header field, which wraps to ~65530, and the following memmove() writes mac_len bytes ~64KiB past skb->head.

A single AF_INET6/SOCK_RAW/IPV6_HDRINCL packet over lo with a two segment type-3 SRH (CmprI=0, CmprE=15) reaches headroom 8 after one pass; KASAN reports a 14-byte OOB write in ipv6_rthdr_rcv.

Fix this by expanding the head whenever the remaining room is less than the push size plus mac_len, and request that much extra so the rebuilt MAC header fits afterwards.

CVSS Base Scores

version 3.1