| 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-2024-41084: cxl/region: Avoid null pointer dereference in region lookup |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| cxl/region: Avoid null pointer dereference in region lookup |
| |
| cxl_dpa_to_region() looks up a region based on a memdev and DPA. |
| It wrongly assumes an endpoint found mapping the DPA is also of |
| a fully assembled region. When not true it leads to a null pointer |
| dereference looking up the region name. |
| |
| This appears during testing of region lookup after a failure to |
| assemble a BIOS defined region or if the lookup raced with the |
| assembly of the BIOS defined region. |
| |
| Failure to clean up BIOS defined regions that fail assembly is an |
| issue in itself and a fix to that problem will alleviate some of |
| the impact. It will not alleviate the race condition so let's harden |
| this path. |
| |
| The behavior change is that the kernel oops due to a null pointer |
| dereference is replaced with a dev_dbg() message noting that an |
| endpoint was mapped. |
| |
| Additional comments are added so that future users of this function |
| can more clearly understand what it provides. |
| |
| The Linux kernel CVE team has assigned CVE-2024-41084 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.4 with commit 0a105ab28a4de44eb738ce64e9ac74946aa5133b and fixed in 6.6.37 with commit a9e099e29e925f8b31cfe53e8a786b9796f8e453 |
| Issue introduced in 6.4 with commit 0a105ab28a4de44eb738ce64e9ac74946aa5133b and fixed in 6.9.8 with commit b8a40a6dbfb0150c1081384caa9bbe28ce5d5060 |
| Issue introduced in 6.4 with commit 0a105ab28a4de44eb738ce64e9ac74946aa5133b and fixed in 6.10 with commit 285f2a08841432fc3e498b1cd00cce5216cdf189 |
| |
| 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-2024-41084 |
| 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: |
| drivers/cxl/core/region.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/a9e099e29e925f8b31cfe53e8a786b9796f8e453 |
| https://git.kernel.org/stable/c/b8a40a6dbfb0150c1081384caa9bbe28ce5d5060 |
| https://git.kernel.org/stable/c/285f2a08841432fc3e498b1cd00cce5216cdf189 |
