In the Linux kernel, the following vulnerability has been resolved:
ipv6: icmp: clear skb2->cb[] in ip6_err_gen_icmpv6_unreach()
Sashiko AI-review observed:
In ip6_err_gen_icmpv6_unreach(), the skb is an outer IPv4 ICMP error packet
where its cb contains an IPv4 inet_skb_parm. When skb is cloned into skb2
and passed to icmp6_send(), it uses IP6CB(skb2).
IP6CB interprets the IPv4 inet_skb_parm as an inet6_skb_parm. The cipso
offset in inet_skb_parm.opt directly overlaps with dsthao in inet6_skb_parm
at offset 18.
If an attacker sends a forged ICMPv4 error with a CIPSO IP option, dsthao
would be a non-zero offset. Inside icmp6_send(), mip6_addr_swap() is called
and uses ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO).
This would scan the inner, attacker-controlled IPv6 packet starting at that
offset, potentially returning a fake TLV without checking if the remaining
packet length can hold the full 18-byte struct ipv6_destopt_hao.
Could mip6_addr_swap() then perform a 16-byte swap that extends past the end
of the packet data into skb_shared_info?
Should the cb array also be cleared in ip6_err_gen_icmpv6_unreach() and
ip6ip6_err() to prevent this?
This patch implements the first suggestion.
I am not sure if ip6ip6_err() needs to be changed.
A separate patch would be better anyway.
References
Configurations
Configuration 1 (hide)
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History
08 May 2026, 18:47
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:3.13:-:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:3.13:rc7:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:3.13:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:3.13:rc8:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:3.13:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:3.13:rc6:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:3.13:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* |
|
| First Time |
Linux linux Kernel
Linux |
|
| CWE | NVD-CWE-noinfo | |
| References | () https://git.kernel.org/stable/c/0452b6526b2f54b2413b9cb4ff1ea2ac542c99c7 - Patch | |
| References | () https://git.kernel.org/stable/c/1ceeebd5bd6d855b17a5df625109bfe29129d7cf - Patch | |
| References | () https://git.kernel.org/stable/c/3d5127d998de617b130aae96b138dba22ac6a8a7 - Patch | |
| References | () https://git.kernel.org/stable/c/86ab3e55673a7a49a841838776f1ab18d23a67b5 - Patch | |
| References | () https://git.kernel.org/stable/c/a2edbb6393972a02114b6003953a5cef3104fada - Patch | |
| References | () https://git.kernel.org/stable/c/a4437faf135da293d16fcc4cc607316742bd0ebb - Patch | |
| References | () https://git.kernel.org/stable/c/c438ba010171b70bad22fc18b1d5bdc3627476e8 - Patch | |
| References | () https://git.kernel.org/stable/c/e41953e7d118e2702bcb217879c173d9d1d3cd4e - Patch |
03 May 2026, 07:16
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 9.8 |
01 May 2026, 15:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-01 15:16
Updated : 2026-05-08 18:47
NVD link : CVE-2026-43038
Mitre link : CVE-2026-43038
CVE.ORG link : CVE-2026-43038
JSON object : View
Products Affected
linux
- linux_kernel
CWE