{"id":"CVE-2026-68235","summary":"drm/amd/display: dce100: skip non-DP stream encoders for DP MST","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: dce100: skip non-DP stream encoders for DP MST\n\nOn DCE8-class ASICs (e.g. Bonaire), the resource pool contains digital\nDIG stream encoders plus one analog DAC encoder. When assigning a stream\nencoder for a second DisplayPort MST stream, if the preferred digital\nencoder is already acquired, dce100_find_first_free_match_stream_enc_for_link()\nfalls back to the first free pool entry. That entry may be the analog\nencoder, whose funcs table lacks DP hooks such as dp_set_stream_attribute.\nThe subsequent atomic commit then dereferences NULL function pointers in\nlink_set_dpms_on() and crashes.\n\nSkip encoders without dp_set_stream_attribute when the stream uses a DP\nsignal (including MST). Use dc_is_dp_signal(stream-\u003esignal) for the MST\nfallback path instead of checking only the link connector signal.\n\nTested on:\n- GPU: AMD Radeon R7 260X (Bonaire / DCE8)\n- Board: Supermicro C9X299-PG300\n- Setup: DP MST daisy chain, hotplug second monitor or have it connected on boot\n- Kernel: 7.1.3 (issue observed since 6.19)\n- Result: kernel oops without patch; dual monitors stable with patch\n\n(cherry picked from commit 28ec64943e3ee4d9b8d30cea61e380f1429953a8)","modified":"2026-08-20T03:36:27.862913855Z","published":"2026-08-10T12:01:00.099Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68235.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/d340cba0df4cf327c7e89c7c1a4e79d4771d7dd5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ed2d86aef9fa4c43f82da0fca91a60f7326d7d03"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68235.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68235"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5834c33fd3f6f2a26dd4d6d4bbc7b8ed1c2ac4aa"},{"fixed":"ed2d86aef9fa4c43f82da0fca91a60f7326d7d03"},{"fixed":"d340cba0df4cf327c7e89c7c1a4e79d4771d7dd5"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-68235.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-68235.json"}}],"schema_version":"1.9.0"}