{"id":"AZL-110849","summary":"CVE-2026-99007 affecting package kernel 6.6.157.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/fb-helper: defer setup when fbdev_probe() fails, not just on -EAGAIN\n\n__drm_fb_helper_initial_config_and_unlock() calls\ndrm_client_modeset_probe() first, which already fills in each\nmode_set-\u003emode/num_connectors for every connected output, and only\nafterwards calls drm_fb_helper_single_fb_probe() to create\nfb_helper-\u003efb and wire it into those mode_sets via\ndrm_setup_crtcs_fb().\n\nIf drm_fb_helper_single_fb_probe() fails with anything other than\n-EAGAIN (e.g. dev-\u003edriver-\u003efbdev_probe() itself fails), the function\nbails out before drm_setup_crtcs_fb() runs and before setting\nfb_helper-\u003edeferred_setup. The client is left with mode_sets that\nhave a mode and connectors but mode_set-\u003efb == NULL, and nothing\nmarks this fb_helper as needing a retry.\n\n__drm_fb_helper_restore_fbdev_mode_unlocked() only skips committing\nwhen fb_helper-\u003edeferred_setup is set, so a later .restore() call\n(drm_lastclose() on process exit, in this report) commits the stale\nmode_set through drm_client_modeset_commit() -\u003e\ndrm_client_modeset_commit_atomic() -\u003e __drm_atomic_helper_set_config(),\nwhich hits WARN_ON(!set-\u003efb).\n\nMark fb_helper-\u003edeferred_setup on any drm_fb_helper_single_fb_probe()\nfailure, not just -EAGAIN, so restore keeps skipping the commit until\na later hotplug event successfully re-probes and re-populates\nmode_set-\u003efb. The real error code is still returned to the caller\nunchanged.","modified":"2026-10-25T05:30:37Z","published":"2026-10-23T13:17:23Z","upstream":["CVE-2026-99007"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99007"}],"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-110849.json"}}],"schema_version":"1.9.0"}