| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2025-21768: net: ipv6: fix dst ref loops in rpl, seg6 and ioam6 lwtunnels |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| net: ipv6: fix dst ref loops in rpl, seg6 and ioam6 lwtunnels |
| |
| Some lwtunnels have a dst cache for post-transformation dst. |
| If the packet destination did not change we may end up recording |
| a reference to the lwtunnel in its own cache, and the lwtunnel |
| state will never be freed. |
| |
| Discovered by the ioam6.sh test, kmemleak was recently fixed |
| to catch per-cpu memory leaks. I'm not sure if rpl and seg6 |
| can actually hit this, but in principle I don't see why not. |
| |
| The Linux kernel CVE team has assigned CVE-2025-21768 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.10 with commit 6c8702c60b88651072460f3f4026c7dfe2521d12 and fixed in 6.12.16 with commit 5ab11a4e219e93b8b31a27f8ec98d42afadd8b7a |
| Issue introduced in 4.10 with commit 6c8702c60b88651072460f3f4026c7dfe2521d12 and fixed in 6.13.4 with commit 4c0f200c7d06fedddde82209c099014d63f4a6c0 |
| Issue introduced in 4.10 with commit 6c8702c60b88651072460f3f4026c7dfe2521d12 and fixed in 6.14 with commit 92191dd1073088753821b862b791dcc83e558e07 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2025-21768 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| net/ipv6/ioam6_iptunnel.c |
| net/ipv6/rpl_iptunnel.c |
| net/ipv6/seg6_iptunnel.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/5ab11a4e219e93b8b31a27f8ec98d42afadd8b7a |
| https://git.kernel.org/stable/c/4c0f200c7d06fedddde82209c099014d63f4a6c0 |
| https://git.kernel.org/stable/c/92191dd1073088753821b862b791dcc83e558e07 |
