CyberRota Analysis
AI-GeneratedThe vulnerability in the Linux kernel affects the handling of operation bindings in the drm/xe subsystem, where the failure to reset the `current_op` variable can lead to out-of-bounds writes and potential use-after-free (UAF) crashes. This issue primarily impacts systems utilizing the Direct Rendering Manager (DRM) for graphics operations, particularly under conditions of lock contention or out-of-memory (OOM) scenarios. Organizations running Linux environments with graphics processing capabilities should prioritize this vulnerability to prevent instability and potential exploitation.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: drm/xe/pt: Reset current_op in xe_pt_update_ops_init() xe_pt_update_ops_init() fails to reset current_op to 0. On the vm_bind path, ops_execute() calls xe_pt_update_ops_prepare() inside the xe_validation_guard() / drm_exec_until_all_locked() loop. When that loop retries due to lock contention or OOM eviction (drm_exec_retry_on_contention() / xe_validation_retry_on_oom()), xe_pt_update_ops_prepare() runs again on the same vops, and each call to bind_op_prepare() increments current_op without resetting it. After N retries current_op exceeds the array size allocated by xe_vma_ops_alloc(), causing an out-of-bounds write into SLUB-poisoned memory and a subsequent UAF crash in xe_migrate_update_pgtables_cpu() when reading the corrupted pt_op->bind. Also reset needs_svm_lock and needs_invalidation which are derived in the same prepare pass and would otherwise cause wrong migrate ops selection and redundant TLB invalidation on retry. Fix this by resetting current_op, needs_svm_lock and needs_invalidation in xe_pt_update_ops_init(). v2 (Matt): - Add details in commit message. - Add Fixes tag and Cc to stable@vger.kernel.org (cherry picked from commit 046045543e530605c441063535e7dca0075369a6)