{"id":"CVE-2026-97900","summary":"drm/drm_exec: fix up contended obj when num_objects is 0","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/drm_exec: fix up contended obj when num_objects is 0\n\ndrm_exec_prepare_array() silently returns success without calling\ndrm_exec_lock_contended() when num_objects is zero. This breaks the\ninvariant upheld by drm_exec_lock_obj(), where every entry point into\nthe locking sequence must first attempt to lock any previously\ncontended object before proceeding.\n\nDrivers that chain multiple drm_exec_prepare_array() calls per\ndrm_exec_until_all_locked() iteration (e.g. amdgpu's userq signal/wait\nioctls, which prepare separate read and write BO arrays) can pass an\nempty array for one of the two calls. If contention is hit while\npreparing the non-empty array, exec-\u003econtended is set and the loop\nretries; on retry, the empty-array call preceding it is a no-op that\nnever clears exec-\u003econtended, so drm_exec_retry_on_contention()\nimmediately jumps back to the top of the loop without ever reaching\nthe call that would resolve the contention. This spins forever.\n\nFix it by having drm_exec_prepare_array() call drm_exec_lock_contended()\ndirectly when num_objects is zero, so a pending contended object dont\nloop infinitely.","modified":"2026-09-27T03:47:31.968802273Z","published":"2026-09-25T10:22:28.057Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97900.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/159720704d9d652b64390c11fb971e15b0a78d23"},{"type":"WEB","url":"https://git.kernel.org/stable/c/831cd124ce99c3e61266bed30519d52f7c26abed"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a565022c02f218ec9789c2baf4690792e7a48cbb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f3e74866018dab793ebee1fdf0ef34f7271d1f8c"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97900.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97900"},{"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":"09593216bff15866f95c8ad406cb7fdcec1ee40a"},{"fixed":"831cd124ce99c3e61266bed30519d52f7c26abed"},{"fixed":"f3e74866018dab793ebee1fdf0ef34f7271d1f8c"},{"fixed":"a565022c02f218ec9789c2baf4690792e7a48cbb"},{"fixed":"159720704d9d652b64390c11fb971e15b0a78d23"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-97900.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.6.0"},{"fixed":"6.12.111"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.53"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.7"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-97900.json"}}],"schema_version":"1.9.0"}