| From bippy-1.1.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2022-49895: cxl/region: Fix decoder allocation crash |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| cxl/region: Fix decoder allocation crash |
| |
| When an intermediate port's decoders have been exhausted by existing |
| regions, and creating a new region with the port in question in it's |
| hierarchical path is attempted, cxl_port_attach_region() fails to find a |
| port decoder (as would be expected), and drops into the failure / cleanup |
| path. |
| |
| However, during cleanup of the region reference, a sanity check attempts |
| to dereference the decoder, which in the above case didn't exist. This |
| causes a NULL pointer dereference BUG. |
| |
| To fix this, refactor the decoder allocation and de-allocation into |
| helper routines, and in this 'free' routine, check that the decoder, |
| @cxld, is valid before attempting any operations on it. |
| |
| The Linux kernel CVE team has assigned CVE-2022-49895 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.0 with commit 384e624bb211b406db40edc900bb51af8bb267d0 and fixed in 6.0.8 with commit c6813b5610ac53af73edd87a660d23a0511faa47 |
| Issue introduced in 6.0 with commit 384e624bb211b406db40edc900bb51af8bb267d0 and fixed in 6.1 with commit 71ee71d7adcba648077997a29a91158d20c40b09 |
| |
| 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-2022-49895 |
| 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/c6813b5610ac53af73edd87a660d23a0511faa47 |
| https://git.kernel.org/stable/c/71ee71d7adcba648077997a29a91158d20c40b09 |
