| From bippy-7c5fe7eed585 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-2025-21972: net: mctp: unshare packets when reassembling |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| net: mctp: unshare packets when reassembling |
| |
| Ensure that the frag_list used for reassembly isn't shared with other |
| packets. This avoids incorrect reassembly when packets are cloned, and |
| prevents a memory leak due to circular references between fragments and |
| their skb_shared_info. |
| |
| The upcoming MCTP-over-USB driver uses skb_clone which can trigger the |
| problem - other MCTP drivers don't share SKBs. |
| |
| A kunit test is added to reproduce the issue. |
| |
| The Linux kernel CVE team has assigned CVE-2025-21972 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.15 with commit 4a992bbd365094730a31bae1e12a6ca695336d57 and fixed in 6.12.20 with commit 5c47d5bfa7b096cf8890afac32141c578583f8e0 |
| Issue introduced in 5.15 with commit 4a992bbd365094730a31bae1e12a6ca695336d57 and fixed in 6.13.8 with commit f44fff3d3c6cd67b6f348b821d73c4d6888c7a6e |
| Issue introduced in 5.15 with commit 4a992bbd365094730a31bae1e12a6ca695336d57 and fixed in 6.14 with commit f5d83cf0eeb90fade4d5c4d17d24b8bee9ceeecc |
| |
| 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-2025-21972 |
| 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/mctp/route.c |
| net/mctp/test/route-test.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/5c47d5bfa7b096cf8890afac32141c578583f8e0 |
| https://git.kernel.org/stable/c/f44fff3d3c6cd67b6f348b821d73c4d6888c7a6e |
| https://git.kernel.org/stable/c/f5d83cf0eeb90fade4d5c4d17d24b8bee9ceeecc |
