CVE-2026-89809

CVE-2026-89809 · drm/amdkfd: fix scope of mqd_mgr dereference in pqm_debugfs_mqds

Cette page présente des faits issus de sources publiques. Consultez l’avis original avant toute mise à jour.

Cette page présente une partie des faits des sources. Consultez les avis liés pour la description complète et les versions concernées.

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: fix scope of mqd_mgr dereference in pqm_debugfs_mqds Reading /sys/kernel/debug/kfd/mqds while a process holds an active KFD queue triggers a NULL pointer dereference because the for loop that calls mqd_mgr->debugfs_show_mqd() is incorrectly placed outside the if (pqn->q) block that initializes mqd_mgr. The queue list can contain entries where pqn->q is NULL (kernel queues where only pqn->kq is valid). In the original code: if (pqn->q) { ... mqd_mgr = q->device->dqm->mqd_mgrs[mqd_type]; size = mqd_mgr->mqd_stride(...); } for (xcc = 0; xcc < num_xccs; xcc++) { // WRONG: outside if block mqd = q->mqd + size * xcc; r = mqd_mgr->debugfs_show_mqd(m, mqd); } When iterating over a queue node where pqn->q is NULL: 1. The if (pqn->q) block is skipped 2. mqd_mgr remains uninitialized (NULL from declaration) 3. The for loop executes anyway 4. mqd_mgr->debugfs_show_mqd(m, mqd) dereferences NULL The crash manifests as: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode RIP: 0010:0x0 Call Trace: pqm_debugfs_mqds+0x10c/0x1d0 [amdgpu] kfd_debugfs_mqds_by_process+0x9b/0x110 [amdgpu] seq_read_iter+0x132/0x4b0 ... Fix by moving the for loop inside the if (pqn->q) block, so mqd_mgr and related variables are only used when properly initialized. (cherry picked from commit 8bfe29d5c798940f797aa24135d2734c3ffce9de)

EPSS 0,2% · Correctif disponible

Publication

2026-09-16T10:30:42.445Z

Mise à jour

2026-10-19T08:53:03.694Z

Pile logicielle: system

Vérifiez votre serveur →