{"id":"CVE-2026-98344","summary":"dmaengine: Fix device kref underflow in dma_chan_put()","details":"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-\u003edevice-\u003eref only on the slow path:\n\n\t/* no kref on fast path */\n\tif (chan-\u003eclient_count) {\n\t\t__module_get(owner);\n\t\tchan-\u003eclient_count++;\n\t\treturn 0;\n\t}\n\tif (!try_module_get(owner))\n\t\treturn -ENODEV;\n\tif (!dma_device_get(chan-\u003edevice)) { // 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-\u003eclient_count \u003e 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-\u003eref only on the last put, matching the\nsingle slow-path get.","modified":"2026-10-07T02:47:32.172270305Z","published":"2026-10-06T08:46:33.997Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98344.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/036b527f92570206da4b8c40b38f8d689e29d0f3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1a0d9b406febf23054ad595fd47b29325e70fb2d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/44dab659064eb5c10adb0306510eebe848ed592d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/57f7f1c6827be7d8f80feca48d2125fb91c6f6ed"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5fb1797a8c9485e40e5492fa0338ab5c7d1f3fef"},{"type":"WEB","url":"https://git.kernel.org/stable/c/77906ac448d2fa81fa710ae26c0e591ebdc81154"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7c3f4ce651d43705f9ec7f778f642a90d5ff4fba"},{"type":"WEB","url":"https://git.kernel.org/stable/c/de2677e57d3161390d8a508f08cddec6ef7e4b23"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98344.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98344"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"8ad342a863590b24ce77681b7e081363fb3333f7"},{"fixed":"036b527f92570206da4b8c40b38f8d689e29d0f3"},{"fixed":"5fb1797a8c9485e40e5492fa0338ab5c7d1f3fef"},{"fixed":"57f7f1c6827be7d8f80feca48d2125fb91c6f6ed"},{"fixed":"7c3f4ce651d43705f9ec7f778f642a90d5ff4fba"},{"fixed":"de2677e57d3161390d8a508f08cddec6ef7e4b23"},{"fixed":"1a0d9b406febf23054ad595fd47b29325e70fb2d"},{"fixed":"77906ac448d2fa81fa710ae26c0e591ebdc81154"},{"fixed":"44dab659064eb5c10adb0306510eebe848ed592d"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98344.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.6.0"},{"fixed":"5.10.271"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.222"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.189"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.158"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.112"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.54"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.8"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98344.json"}}],"schema_version":"1.9.0"}