{"id":"CVE-2026-98344","state":"PUBLISHED","title":"dmaengine: Fix device kref underflow in dma_chan_put()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndmaengine: Fix device kref underflow in dma_chan_put()\n\ndma_chan_get() takes chan->device->ref only on the slow path:\n\n\t/* no kref on fast path */\n\tif (chan->client_count) {\n\t\t__module_get(owner);\n\t\tchan->client_count++;\n\t\treturn 0;\n\t}\n\tif (!try_module_get(owner))\n\t\treturn -ENODEV;\n\tif (!dma_device_get(chan->device)) { // calls kref_get_unless_zero()\n\ndma_chan_put() drops the ref unconditionally, so every fast-path\nget/put pair drops one extra device reference.\n\nThe bug fires when two conditions hold together: a non-private\nprovider has a persistent client holding chan->client_count > 0\nand another client cycles dmaengine_get()/dmaengine_put().\nWhen the kref hits zero, the subsequent dma_find_channel() returns\nNULL even though the provider module is still loaded.\n\nFix this by dropping device->ref only on the last put, matching the\nsingle slow-path get.","publishedAt":"2026-10-06T08:46:33.997Z","updatedAt":"2026-10-19T09:17:55.263Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8ad342a863590b24ce77681b7e081363fb3333f7","status":"affected","lessThan":"036b527f92570206da4b8c40b38f8d689e29d0f3","versionType":"git"},{"version":"8ad342a863590b24ce77681b7e081363fb3333f7","status":"affected","lessThan":"5fb1797a8c9485e40e5492fa0338ab5c7d1f3fef","versionType":"git"},{"version":"8ad342a863590b24ce77681b7e081363fb3333f7","status":"affected","lessThan":"57f7f1c6827be7d8f80feca48d2125fb91c6f6ed","versionType":"git"},{"version":"8ad342a863590b24ce77681b7e081363fb3333f7","status":"affected","lessThan":"7c3f4ce651d43705f9ec7f778f642a90d5ff4fba","versionType":"git"},{"version":"8ad342a863590b24ce77681b7e081363fb3333f7","status":"affected","lessThan":"de2677e57d3161390d8a508f08cddec6ef7e4b23","versionType":"git"},{"version":"8ad342a863590b24ce77681b7e081363fb3333f7","status":"affected","lessThan":"1a0d9b406febf23054ad595fd47b29325e70fb2d","versionType":"git"},{"version":"8ad342a863590b24ce77681b7e081363fb3333f7","status":"affected","lessThan":"77906ac448d2fa81fa710ae26c0e591ebdc81154","versionType":"git"},{"version":"8ad342a863590b24ce77681b7e081363fb3333f7","status":"affected","lessThan":"44dab659064eb5c10adb0306510eebe848ed592d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/dma/dmaengine.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.6","versionType":"semver"},{"version":"5.10.271","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.222","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.54","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.8","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/dma/dmaengine.c"]}],"references":["https://git.kernel.org/stable/c/036b527f92570206da4b8c40b38f8d689e29d0f3","https://git.kernel.org/stable/c/5fb1797a8c9485e40e5492fa0338ab5c7d1f3fef","https://git.kernel.org/stable/c/57f7f1c6827be7d8f80feca48d2125fb91c6f6ed","https://git.kernel.org/stable/c/7c3f4ce651d43705f9ec7f778f642a90d5ff4fba","https://git.kernel.org/stable/c/de2677e57d3161390d8a508f08cddec6ef7e4b23","https://git.kernel.org/stable/c/1a0d9b406febf23054ad595fd47b29325e70fb2d","https://git.kernel.org/stable/c/77906ac448d2fa81fa710ae26c0e591ebdc81154","https://git.kernel.org/stable/c/44dab659064eb5c10adb0306510eebe848ed592d"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98344.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98344","state":"PUBLISHED","datePublished":"2026-10-06T08:46:33.997Z","dateUpdated":"2026-10-19T09:17:55.263Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.343Z"},"containers":{"cna":{"title":"dmaengine: Fix device kref underflow in dma_chan_put()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndmaengine: Fix device kref underflow in dma_chan_put()\n\ndma_chan_get() takes chan->device->ref only on the slow path:\n\n\t/* no kref on fast path */\n\tif (chan->client_count) {\n\t\t__module_get(owner);\n\t\tchan->client_count++;\n\t\treturn 0;\n\t}\n\tif (!try_module_get(owner))\n\t\treturn -ENODEV;\n\tif (!dma_device_get(chan->device)) { // calls kref_get_unless_zero()\n\ndma_chan_put() drops the ref unconditionally, so every fast-path\nget/put pair drops one extra device reference.\n\nThe bug fires when two conditions hold together: a non-private\nprovider has a persistent client holding chan->client_count > 0\nand another client cycles dmaengine_get()/dmaengine_put().\nWhen the kref hits zero, the subsequent dma_find_channel() returns\nNULL even though the provider module is still loaded.\n\nFix this by dropping device->ref only on the last put, matching the\nsingle slow-path get."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8ad342a863590b24ce77681b7e081363fb3333f7","status":"affected","lessThan":"036b527f92570206da4b8c40b38f8d689e29d0f3","versionType":"git"},{"version":"8ad342a863590b24ce77681b7e081363fb3333f7","status":"affected","lessThan":"5fb1797a8c9485e40e5492fa0338ab5c7d1f3fef","versionType":"git"},{"version":"8ad342a863590b24ce77681b7e081363fb3333f7","status":"affected","lessThan":"57f7f1c6827be7d8f80feca48d2125fb91c6f6ed","versionType":"git"},{"version":"8ad342a863590b24ce77681b7e081363fb3333f7","status":"affected","lessThan":"7c3f4ce651d43705f9ec7f778f642a90d5ff4fba","versionType":"git"},{"version":"8ad342a863590b24ce77681b7e081363fb3333f7","status":"affected","lessThan":"de2677e57d3161390d8a508f08cddec6ef7e4b23","versionType":"git"},{"version":"8ad342a863590b24ce77681b7e081363fb3333f7","status":"affected","lessThan":"1a0d9b406febf23054ad595fd47b29325e70fb2d","versionType":"git"},{"version":"8ad342a863590b24ce77681b7e081363fb3333f7","status":"affected","lessThan":"77906ac448d2fa81fa710ae26c0e591ebdc81154","versionType":"git"},{"version":"8ad342a863590b24ce77681b7e081363fb3333f7","status":"affected","lessThan":"44dab659064eb5c10adb0306510eebe848ed592d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/dma/dmaengine.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.6","versionType":"semver"},{"version":"5.10.271","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.222","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.54","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.8","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/dma/dmaengine.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/036b527f92570206da4b8c40b38f8d689e29d0f3"},{"url":"https://git.kernel.org/stable/c/5fb1797a8c9485e40e5492fa0338ab5c7d1f3fef"},{"url":"https://git.kernel.org/stable/c/57f7f1c6827be7d8f80feca48d2125fb91c6f6ed"},{"url":"https://git.kernel.org/stable/c/7c3f4ce651d43705f9ec7f778f642a90d5ff4fba"},{"url":"https://git.kernel.org/stable/c/de2677e57d3161390d8a508f08cddec6ef7e4b23"},{"url":"https://git.kernel.org/stable/c/1a0d9b406febf23054ad595fd47b29325e70fb2d"},{"url":"https://git.kernel.org/stable/c/77906ac448d2fa81fa710ae26c0e591ebdc81154"},{"url":"https://git.kernel.org/stable/c/44dab659064eb5c10adb0306510eebe848ed592d"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:17:55.263Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"5.10.271"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"5.15.222"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"6.1.189"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"6.6.158"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"6.12.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"6.18.54"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"7.2.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}