| 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-2024-26826: mptcp: fix data re-injection from stale subflow |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| mptcp: fix data re-injection from stale subflow |
| |
| When the MPTCP PM detects that a subflow is stale, all the packet |
| scheduler must re-inject all the mptcp-level unacked data. To avoid |
| acquiring unneeded locks, it first try to check if any unacked data |
| is present at all in the RTX queue, but such check is currently |
| broken, as it uses TCP-specific helper on an MPTCP socket. |
| |
| Funnily enough fuzzers and static checkers are happy, as the accessed |
| memory still belongs to the mptcp_sock struct, and even from a |
| functional perspective the recovery completed successfully, as |
| the short-cut test always failed. |
| |
| A recent unrelated TCP change - commit d5fed5addb2b ("tcp: reorganize |
| tcp_sock fast path variables") - exposed the issue, as the tcp field |
| reorganization makes the mptcp code always skip the re-inection. |
| |
| Fix the issue dropping the bogus call: we are on a slow path, the early |
| optimization proved once again to be evil. |
| |
| The Linux kernel CVE team has assigned CVE-2024-26826 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.15 with commit 1e1d9d6f119c55c05e8ea78ed3e49046690abffd and fixed in 5.15.149 with commit 6f95120f898b40d13fd441225ef511307853c9c2 |
| Issue introduced in 5.15 with commit 1e1d9d6f119c55c05e8ea78ed3e49046690abffd and fixed in 6.1.79 with commit 6673d9f1c2cd984390550dbdf7d5ae07b20abbf8 |
| Issue introduced in 5.15 with commit 1e1d9d6f119c55c05e8ea78ed3e49046690abffd and fixed in 6.6.18 with commit b609c783c535493aa3fca22c7e40a120370b1ca5 |
| Issue introduced in 5.15 with commit 1e1d9d6f119c55c05e8ea78ed3e49046690abffd and fixed in 6.7.6 with commit 624902eab7abcb8731b333ec73f206d38d839cd8 |
| Issue introduced in 5.15 with commit 1e1d9d6f119c55c05e8ea78ed3e49046690abffd and fixed in 6.8 with commit b6c620dc43ccb4e802894e54b651cf81495e9598 |
| |
| 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-2024-26826 |
| 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/mptcp/protocol.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/6f95120f898b40d13fd441225ef511307853c9c2 |
| https://git.kernel.org/stable/c/6673d9f1c2cd984390550dbdf7d5ae07b20abbf8 |
| https://git.kernel.org/stable/c/b609c783c535493aa3fca22c7e40a120370b1ca5 |
| https://git.kernel.org/stable/c/624902eab7abcb8731b333ec73f206d38d839cd8 |
| https://git.kernel.org/stable/c/b6c620dc43ccb4e802894e54b651cf81495e9598 |
