| 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-2024-40970: Avoid hw_desc array overrun in dw-axi-dmac |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| Avoid hw_desc array overrun in dw-axi-dmac |
| |
| I have a use case where nr_buffers = 3 and in which each descriptor is composed by 3 |
| segments, resulting in the DMA channel descs_allocated to be 9. Since axi_desc_put() |
| handles the hw_desc considering the descs_allocated, this scenario would result in a |
| kernel panic (hw_desc array will be overrun). |
| |
| To fix this, the proposal is to add a new member to the axi_dma_desc structure, |
| where we keep the number of allocated hw_descs (axi_desc_alloc()) and use it in |
| axi_desc_put() to handle the hw_desc array correctly. |
| |
| Additionally I propose to remove the axi_chan_start_first_queued() call after completing |
| the transfer, since it was identified that unbalance can occur (started descriptors can |
| be interrupted and transfer ignored due to DMA channel not being enabled). |
| |
| The Linux kernel CVE team has assigned CVE-2024-40970 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.15.162 with commit 7c3bb96a20cd8db3b8824b2ff08b6cde4505c7e5 |
| Fixed in 6.1.96 with commit dd42570018f5962c10f215ad9c21274ed5d3541e |
| Fixed in 6.6.36 with commit e151ae1ee065cf4b8ce4394ddb9d9c8df6370c66 |
| Fixed in 6.9.7 with commit 9004784e8d68bcd1ac1376407ba296fa28f04dbe |
| Fixed in 6.10 with commit 333e11bf47fa8d477db90e2900b1ed3c9ae9b697 |
| |
| 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-2024-40970 |
| 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/dma/dw-axi-dmac/dw-axi-dmac-platform.c |
| drivers/dma/dw-axi-dmac/dw-axi-dmac.h |
| |
| |
| 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/7c3bb96a20cd8db3b8824b2ff08b6cde4505c7e5 |
| https://git.kernel.org/stable/c/dd42570018f5962c10f215ad9c21274ed5d3541e |
| https://git.kernel.org/stable/c/e151ae1ee065cf4b8ce4394ddb9d9c8df6370c66 |
| https://git.kernel.org/stable/c/9004784e8d68bcd1ac1376407ba296fa28f04dbe |
| https://git.kernel.org/stable/c/333e11bf47fa8d477db90e2900b1ed3c9ae9b697 |
