From: Zongyao Bai Date: Tue, 14 Jul 2026 23:24:32 +0000 (+0000) Subject: drm/xe/pt: Reset current_op in xe_pt_update_ops_init() X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6384271ac1ac0099198d15df79212a19ebdb929d;p=thirdparty%2Fkernel%2Flinux.git 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 Fixes: e8babb280b5e ("drm/xe: Convert multiple bind ops into single job") Suggested-by: Matthew Auld Cc: stable@vger.kernel.org Assisted-by: GitHub-Copilot:claude-sonnet-4.6 Signed-off-by: Zongyao Bai Reviewed-by: Matthew Brost Signed-off-by: Matthew Brost Link: https://patch.msgid.link/20260714232433.2737533-1-zongyao.bai@intel.com (cherry picked from commit 046045543e530605c441063535e7dca0075369a6) Signed-off-by: Thomas Hellström --- diff --git a/drivers/gpu/drm/xe/xe_pt.c b/drivers/gpu/drm/xe/xe_pt.c index e787c0c27c42..39c9c8f0ea2d 100644 --- a/drivers/gpu/drm/xe/xe_pt.c +++ b/drivers/gpu/drm/xe/xe_pt.c @@ -2365,8 +2365,11 @@ static void xe_pt_update_ops_init(struct xe_vm_pgtable_update_ops *pt_update_ops) { init_llist_head(&pt_update_ops->deferred); + pt_update_ops->current_op = 0; pt_update_ops->start = ~0x0ull; pt_update_ops->last = 0x0ull; + pt_update_ops->needs_svm_lock = false; + pt_update_ops->needs_invalidation = false; xe_page_reclaim_list_init(&pt_update_ops->prl); }