{"id":"AZL-106251","summary":"CVE-2026-98344 affecting package kernel 6.6.157.1-1","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":"2026-10-07T14:17:00.653224910Z","published":"2026-10-06T09:18:27Z","upstream":["CVE-2026-98344"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98344"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.157.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-106251.json"}}],"schema_version":"1.9.0"}