CVE-2026-68264

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> drm/xe/pt: Reset current_op in xe_pt_update_ops_init()<br /> <br /> xe_pt_update_ops_init() fails to reset current_op to 0. On the<br /> vm_bind path, ops_execute() calls xe_pt_update_ops_prepare() inside<br /> the xe_validation_guard() / drm_exec_until_all_locked() loop. When<br /> that loop retries due to lock contention or OOM eviction<br /> (drm_exec_retry_on_contention() / xe_validation_retry_on_oom()),<br /> xe_pt_update_ops_prepare() runs again on the same vops, and each<br /> call to bind_op_prepare() increments current_op without resetting it.<br /> <br /> After N retries current_op exceeds the array size allocated by<br /> xe_vma_ops_alloc(), causing an out-of-bounds write into<br /> SLUB-poisoned memory and a subsequent UAF crash in<br /> xe_migrate_update_pgtables_cpu() when reading the corrupted pt_op-&gt;bind.<br /> <br /> Also reset needs_svm_lock and needs_invalidation which are derived in<br /> the same prepare pass and would otherwise cause wrong migrate ops<br /> selection and redundant TLB invalidation on retry.<br /> <br /> Fix this by resetting current_op, needs_svm_lock and needs_invalidation<br /> in xe_pt_update_ops_init().<br /> <br /> v2 (Matt):<br /> - Add details in commit message.<br /> - Add Fixes tag and Cc to stable@vger.kernel.org<br /> <br /> (cherry picked from commit 046045543e530605c441063535e7dca0075369a6)