{"id":"CVE-2024-40970","state":"PUBLISHED","title":"Avoid hw_desc array overrun in dw-axi-dmac","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nAvoid hw_desc array overrun in dw-axi-dmac\n\nI have a use case where nr_buffers = 3 and in which each descriptor is composed by 3\nsegments, resulting in the DMA channel descs_allocated to be 9. Since axi_desc_put()\nhandles the hw_desc considering the descs_allocated, this scenario would result in a\nkernel panic (hw_desc array will be overrun).\n\nTo fix this, the proposal is to add a new member to the axi_dma_desc structure,\nwhere we keep the number of allocated hw_descs (axi_desc_alloc()) and use it in\naxi_desc_put() to handle the hw_desc array correctly.\n\nAdditionally I propose to remove the axi_chan_start_first_queued() call after completing\nthe transfer, since it was identified that unbalance can occur (started descriptors can\nbe interrupted and transfer ignored due to DMA channel not being enabled).","publishedAt":"2024-07-12T12:32:08.788Z","updatedAt":"2026-08-05T11:34:18.464Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ef6fb2d6f1abd56cc067c694253ea362159b5ac3","status":"affected","lessThan":"7c3bb96a20cd8db3b8824b2ff08b6cde4505c7e5","versionType":"git"},{"version":"ef6fb2d6f1abd56cc067c694253ea362159b5ac3","status":"affected","lessThan":"dd42570018f5962c10f215ad9c21274ed5d3541e","versionType":"git"},{"version":"ef6fb2d6f1abd56cc067c694253ea362159b5ac3","status":"affected","lessThan":"e151ae1ee065cf4b8ce4394ddb9d9c8df6370c66","versionType":"git"},{"version":"ef6fb2d6f1abd56cc067c694253ea362159b5ac3","status":"affected","lessThan":"9004784e8d68bcd1ac1376407ba296fa28f04dbe","versionType":"git"},{"version":"ef6fb2d6f1abd56cc067c694253ea362159b5ac3","status":"affected","lessThan":"333e11bf47fa8d477db90e2900b1ed3c9ae9b697","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c","drivers/dma/dw-axi-dmac/dw-axi-dmac.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.12","versionType":"semver"},{"version":"5.15.162","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.96","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.36","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.9.7","status":"unaffected","lessThanOrEqual":"6.9.*","versionType":"semver"},{"version":"6.10","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c","drivers/dma/dw-axi-dmac/dw-axi-dmac.h"]}],"references":["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","https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:07:39.287Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/40xxx/CVE-2024-40970.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-40970","state":"PUBLISHED","datePublished":"2024-07-12T12:32:08.788Z","dateUpdated":"2026-08-05T11:34:18.464Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-07-12T12:17:45.603Z"},"containers":{"cna":{"title":"Avoid hw_desc array overrun in dw-axi-dmac","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nAvoid hw_desc array overrun in dw-axi-dmac\n\nI have a use case where nr_buffers = 3 and in which each descriptor is composed by 3\nsegments, resulting in the DMA channel descs_allocated to be 9. Since axi_desc_put()\nhandles the hw_desc considering the descs_allocated, this scenario would result in a\nkernel panic (hw_desc array will be overrun).\n\nTo fix this, the proposal is to add a new member to the axi_dma_desc structure,\nwhere we keep the number of allocated hw_descs (axi_desc_alloc()) and use it in\naxi_desc_put() to handle the hw_desc array correctly.\n\nAdditionally I propose to remove the axi_chan_start_first_queued() call after completing\nthe transfer, since it was identified that unbalance can occur (started descriptors can\nbe interrupted and transfer ignored due to DMA channel not being enabled)."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ef6fb2d6f1abd56cc067c694253ea362159b5ac3","status":"affected","lessThan":"7c3bb96a20cd8db3b8824b2ff08b6cde4505c7e5","versionType":"git"},{"version":"ef6fb2d6f1abd56cc067c694253ea362159b5ac3","status":"affected","lessThan":"dd42570018f5962c10f215ad9c21274ed5d3541e","versionType":"git"},{"version":"ef6fb2d6f1abd56cc067c694253ea362159b5ac3","status":"affected","lessThan":"e151ae1ee065cf4b8ce4394ddb9d9c8df6370c66","versionType":"git"},{"version":"ef6fb2d6f1abd56cc067c694253ea362159b5ac3","status":"affected","lessThan":"9004784e8d68bcd1ac1376407ba296fa28f04dbe","versionType":"git"},{"version":"ef6fb2d6f1abd56cc067c694253ea362159b5ac3","status":"affected","lessThan":"333e11bf47fa8d477db90e2900b1ed3c9ae9b697","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c","drivers/dma/dw-axi-dmac/dw-axi-dmac.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.12","versionType":"semver"},{"version":"5.15.162","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.96","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.36","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.9.7","status":"unaffected","lessThanOrEqual":"6.9.*","versionType":"semver"},{"version":"6.10","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c","drivers/dma/dw-axi-dmac/dw-axi-dmac.h"]}],"references":[{"url":"https://git.kernel.org/stable/c/7c3bb96a20cd8db3b8824b2ff08b6cde4505c7e5"},{"url":"https://git.kernel.org/stable/c/dd42570018f5962c10f215ad9c21274ed5d3541e"},{"url":"https://git.kernel.org/stable/c/e151ae1ee065cf4b8ce4394ddb9d9c8df6370c66"},{"url":"https://git.kernel.org/stable/c/9004784e8d68bcd1ac1376407ba296fa28f04dbe"},{"url":"https://git.kernel.org/stable/c/333e11bf47fa8d477db90e2900b1ed3c9ae9b697"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The overrun is reached only by driving a local peripheral (audio/serial/SPI device node) whose driver queues multiple DMA descriptors on a dw-axi-dmac channel; no network- or peer-supplied data influences the descriptor accounting. Physical access is not required, so this is local.\nAC:L - The overrun is deterministic whenever two or more descriptors are outstanding on the same channel, a state the attacker arranges simply by queueing several buffers/transfers before stopping the stream. No race or unfavorable memory layout beyond the attacker's control is needed to trigger the panic.\nPR:L - A local unprivileged user with access to a device node backed by this DMA controller (e.g. /dev/snd/pcm*, tty, spidev on the affected RISC-V/ARC/Agilex5/Keem Bay platforms) can drive the prep/terminate cycle. No root or capability check guards the dmaengine client path.\nUI:N - The attacker performs the buffer queueing and stream teardown itself; no action by another user or administrator is required.\nS:U - The out-of-bounds access, the corrupted dma_pool free list, and any resulting DMA writes all occur within the kernel's own security authority. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - The loop reads well past the end of the kmalloc-96 hw_desc array into adjacent slab objects, and the resulting free-list poisoning lets a later dma_pool_alloc() return an attacker-chosen address usable as a read primitive over arbitrary kernel memory. The leak is not bounded to a few bytes.\nI:H - pool_block_push() writes the dma address and next-block pointer at the out-of-bounds-derived vaddr with no validation in the non-DMAPOOL_DEBUG path, and links that address into the pool free list so the DMA engine subsequently writes hardware LLI data there. This yields an arbitrary kernel write suitable for control-flow hijacking.\nA:H - The commit explicitly documents a kernel panic from the hw_desc array overrun, and freeing a NULL/garbage vaddr into the dma pool oopses immediately. The counter underflow from atomic_sub() further corrupts channel state, so the crash is repeatable."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T11:34:18.464Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"5.15.162"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.1.96"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.6.36"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.9.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.10"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/7c3bb96a20cd8db3b8824b2ff08b6cde4505c7e5","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/dd42570018f5962c10f215ad9c21274ed5d3541e","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/e151ae1ee065cf4b8ce4394ddb9d9c8df6370c66","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/9004784e8d68bcd1ac1376407ba296fa28f04dbe","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/333e11bf47fa8d477db90e2900b1ed3c9ae9b697","tags":["x_transferred"]},{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-11-03T21:58:34.724Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2024-40970","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-09-10T17:02:57.618240Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-11T17:34:22.651Z"}}]}}}