From: Ian Forbes Date: Fri, 26 Sep 2025 19:54:25 +0000 (-0500) Subject: drm/vmwgfx: Fix Use-after-free in validation X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=dfe1323ab3c8a4dd5625ebfdba44dc47df84512a;p=users%2Fhch%2Fmisc.git drm/vmwgfx: Fix Use-after-free in validation Nodes stored in the validation duplicates hashtable come from an arena allocator that is cleared at the end of vmw_execbuf_process. All nodes are expected to be cleared in vmw_validation_drop_ht but this node escaped because its resource was destroyed prematurely. Fixes: 64ad2abfe9a6 ("drm/vmwgfx: Adapt validation code for reference-free lookups") Reported-by: Kuzey Arda Bulut Signed-off-by: Ian Forbes Reviewed-by: Zack Rusin Signed-off-by: Zack Rusin Link: https://lore.kernel.org/r/20250926195427.1405237-1-ian.forbes@broadcom.com --- diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c b/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c index 7ee93e7191c7..4d0fb71f6211 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c @@ -308,8 +308,10 @@ int vmw_validation_add_resource(struct vmw_validation_context *ctx, hash_add_rcu(ctx->sw_context->res_ht, &node->hash.head, node->hash.key); } node->res = vmw_resource_reference_unless_doomed(res); - if (!node->res) + if (!node->res) { + hash_del_rcu(&node->hash.head); return -ESRCH; + } node->first_usage = 1; if (!res->dev_priv->has_mob) {