| 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-2023-52517: spi: sun6i: fix race between DMA RX transfer completion and RX FIFO drain |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| spi: sun6i: fix race between DMA RX transfer completion and RX FIFO drain |
| |
| Previously the transfer complete IRQ immediately drained to RX FIFO to |
| read any data remaining in FIFO to the RX buffer. This behaviour is |
| correct when dealing with SPI in interrupt mode. However in DMA mode the |
| transfer complete interrupt still fires as soon as all bytes to be |
| transferred have been stored in the FIFO. At that point data in the FIFO |
| still needs to be picked up by the DMA engine. Thus the drain procedure |
| and DMA engine end up racing to read from RX FIFO, corrupting any data |
| read. Additionally the RX buffer pointer is never adjusted according to |
| DMA progress in DMA mode, thus calling the RX FIFO drain procedure in DMA |
| mode is a bug. |
| Fix corruptions in DMA RX mode by draining RX FIFO only in interrupt mode. |
| Also wait for completion of RX DMA when in DMA mode before returning to |
| ensure all data has been copied to the supplied memory buffer. |
| |
| The Linux kernel CVE team has assigned CVE-2023-52517 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.15.134 with commit bd1ec7f9983b5cd3c77e0f7cda3fa8aed041af2f |
| Fixed in 6.1.56 with commit 36b29974a7ad2ff604c24ad348f940506c7b1209 |
| Fixed in 6.5.6 with commit 4e149d524678431638ff378ef6025e4e89b71097 |
| Fixed in 6.6 with commit 1f11f4202caf5710204d334fe63392052783876d |
| |
| 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-2023-52517 |
| 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/spi/spi-sun6i.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/bd1ec7f9983b5cd3c77e0f7cda3fa8aed041af2f |
| https://git.kernel.org/stable/c/36b29974a7ad2ff604c24ad348f940506c7b1209 |
| https://git.kernel.org/stable/c/4e149d524678431638ff378ef6025e4e89b71097 |
| https://git.kernel.org/stable/c/1f11f4202caf5710204d334fe63392052783876d |
