{"id":"CVE-2026-98344","published":"2026-10-06T09:18:27.323","lastModified":"2026-10-06T09:18:27.323","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.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/036b527f92570206da4b8c40b38f8d689e29d0f3","tags":[]},{"url":"https://git.kernel.org/stable/c/1a0d9b406febf23054ad595fd47b29325e70fb2d","tags":[]},{"url":"https://git.kernel.org/stable/c/44dab659064eb5c10adb0306510eebe848ed592d","tags":[]},{"url":"https://git.kernel.org/stable/c/57f7f1c6827be7d8f80feca48d2125fb91c6f6ed","tags":[]},{"url":"https://git.kernel.org/stable/c/5fb1797a8c9485e40e5492fa0338ab5c7d1f3fef","tags":[]},{"url":"https://git.kernel.org/stable/c/77906ac448d2fa81fa710ae26c0e591ebdc81154","tags":[]},{"url":"https://git.kernel.org/stable/c/7c3f4ce651d43705f9ec7f778f642a90d5ff4fba","tags":[]},{"url":"https://git.kernel.org/stable/c/de2677e57d3161390d8a508f08cddec6ef7e4b23","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}