Bugzilla – Bug 1227899
VUL-0: CVE-2024-40970: kernel: Avoid hw_desc array overrun in dw-axi-dmac
Last modified: 2024-07-16 09:09:57 UTC
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). References: http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-40970 https://www.cve.org/CVERecord?id=CVE-2024-40970 https://git.kernel.org/stable/c/333e11bf47fa8d477db90e2900b1ed3c9ae9b697 https://git.kernel.org/stable/c/7c3bb96a20cd8db3b8824b2ff08b6cde4505c7e5 https://git.kernel.org/stable/c/9004784e8d68bcd1ac1376407ba296fa28f04dbe https://git.kernel.org/stable/c/dd42570018f5962c10f215ad9c21274ed5d3541e https://git.kernel.org/stable/c/e151ae1ee065cf4b8ce4394ddb9d9c8df6370c66 https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-40970.mbox