From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 12387313527; Fri, 7 Aug 2026 15:48:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786117699; cv=none; b=JzY/BuBJTDqXaDOXcyzVxl3O5jnPbxQ1QWcPgKuZie7UAwQgvM2bR/2UczjLvylgYiPtD0nG0T6dWz8xAuVwv0KD7i4pM67cO/Ck6BANPodN9QHFQ75EzXxdlvacRAyuOIubAIIFhRIHObobI+xC4OMWYjo6wXtG6y6ztvCRWlQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786117699; c=relaxed/simple; bh=u6xChClO6BQUOpdF3dHD1hQLav5vBO0K8NM9mnkky9s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ckKDM3wLCLjvE8ZoDms3fYHq0YHTdt4IdVL333i/HTkC7pbjkaThwdsc9twPHflWfiO4dm7sd4pOlntLlkdIardWs2EaOTb+KBN2QC1TvvDWoPz2ZO5cDGI4K9/f2hprs2OR7c47WHplw4rQEWhqeOQNcEfk6e/oqG573uDiIvE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=y+Lfa+oJ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="y+Lfa+oJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 280551F000E9; Fri, 7 Aug 2026 15:48:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786117697; bh=NpjjO9LbZoWaJjTWRnKugktBdG8r10bKwA/PKZt6NrY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=y+Lfa+oJf5AuYF4fv9RlB9C+ps+3cHc2Vdut5EnzHXgnFAPwnNqACT+mnHCw6l7R5 M+lkGRnorNtb9ETePHuXo1OoSpcDtA7Da0pUowTTggLDLCwz/dP6xgDlpj5PAEyhwt 6OxmA5Ng3AGni+StfSIBRXaswFo4cmzJYf9Gkzxs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zack Rusin , Ian Forbes Subject: [PATCH 7.1 411/438] drm/vmwgfx: drop dma_buf reference on foreign-fd prime import Date: Fri, 7 Aug 2026 16:40:07 +0200 Message-ID: <20260807143436.727656885@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260807143428.008222056@linuxfoundation.org> References: <20260807143428.008222056@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zack Rusin commit f739416dc555fa205a785e5135d73fa39b26f35d upstream. ttm_prime_fd_to_handle() returns -ENOSYS when the imported fd's dma_buf->ops do not match the ttm_object_device's ops, but does so without releasing the reference acquired by dma_buf_get(). Any unprivileged renderD client passing a non-vmwgfx prime fd through the DRM_VMW_GB_SURFACE_REF{,_EXT} path leaks one dma_buf reference per call and indefinitely pins the foreign exporter's GEM resources. Funnel the error path through the existing dma_buf_put() so the reference is always dropped. Fixes: 65981f7681ab ("drm/ttm: Add a minimal prime implementation for ttm base objects") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4.7 Signed-off-by: Zack Rusin Reviewed-by: Ian Forbes Link: https://patch.msgid.link/20260505222728.519626-6-zack.rusin@broadcom.com Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/vmwgfx/ttm_object.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/vmwgfx/ttm_object.c +++ b/drivers/gpu/drm/vmwgfx/ttm_object.c @@ -547,14 +547,17 @@ int ttm_prime_fd_to_handle(struct ttm_ob if (IS_ERR(dma_buf)) return PTR_ERR(dma_buf); - if (dma_buf->ops != &tdev->ops) - return -ENOSYS; + if (dma_buf->ops != &tdev->ops) { + ret = -ENOSYS; + goto out; + } prime = (struct ttm_prime_object *) dma_buf->priv; base = &prime->base; *handle = base->handle; ret = ttm_ref_object_add(tfile, base, NULL, false); +out: dma_buf_put(dma_buf); return ret;