From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 021C5C433F5 for ; Mon, 24 Jan 2022 20:42:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1389381AbiAXUku (ORCPT ); Mon, 24 Jan 2022 15:40:50 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:57596 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354599AbiAXUU1 (ORCPT ); Mon, 24 Jan 2022 15:20:27 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A17E9B811FB; Mon, 24 Jan 2022 20:20:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C6B6BC340E5; Mon, 24 Jan 2022 20:20:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643055623; bh=EuZrEE6iroL4h8Fnk2WfPwJrm92ykgsXH1Ll7+avYoc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iiFBibZFbWLkxVsSY0JlDQwh2ONeS7HXQ432XgGui1Z5Wz6CPigyd/6mY2we3NpWq BtRLxznCOUTZf4fCendq0AgpKQ9W/P/UkP9v5bAU1tPzNwOWeE2SgSF3nxGqOlXU27 lIw5PcEEXorukbvIdw0pOdj4U6bD7HBtZmJKgimk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?UTF-8?q?Christian=20K=C3=B6nig?= , Zhou Qingyang , Alex Deucher , Sasha Levin Subject: [PATCH 5.15 184/846] drm/radeon/radeon_kms: Fix a NULL pointer dereference in radeon_driver_open_kms() Date: Mon, 24 Jan 2022 19:35:01 +0100 Message-Id: <20220124184107.319097468@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124184100.867127425@linuxfoundation.org> References: <20220124184100.867127425@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Zhou Qingyang [ Upstream commit ab50cb9df8896b39aae65c537a30de2c79c19735 ] In radeon_driver_open_kms(), radeon_vm_bo_add() is assigned to vm->ib_bo_va and passes and used in radeon_vm_bo_set_addr(). In radeon_vm_bo_set_addr(), there is a dereference of vm->ib_bo_va, which could lead to a NULL pointer dereference on failure of radeon_vm_bo_add(). Fix this bug by adding a check of vm->ib_bo_va. This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs. Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug. Builds with CONFIG_DRM_RADEON=m show no new warnings, and our static analyzer no longer warns about this code. Fixes: cc9e67e3d700 ("drm/radeon: fix VM IB handling") Reviewed-by: Christian König Signed-off-by: Zhou Qingyang Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/radeon/radeon_kms.c | 36 ++++++++++++++++------------- 1 file changed, 20 insertions(+), 16 deletions(-) diff --git a/drivers/gpu/drm/radeon/radeon_kms.c b/drivers/gpu/drm/radeon/radeon_kms.c index 482fb0ae6cb5d..66aee48fd09d2 100644 --- a/drivers/gpu/drm/radeon/radeon_kms.c +++ b/drivers/gpu/drm/radeon/radeon_kms.c @@ -648,6 +648,8 @@ void radeon_driver_lastclose_kms(struct drm_device *dev) int radeon_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv) { struct radeon_device *rdev = dev->dev_private; + struct radeon_fpriv *fpriv; + struct radeon_vm *vm; int r; file_priv->driver_priv = NULL; @@ -660,8 +662,6 @@ int radeon_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv) /* new gpu have virtual address space support */ if (rdev->family >= CHIP_CAYMAN) { - struct radeon_fpriv *fpriv; - struct radeon_vm *vm; fpriv = kzalloc(sizeof(*fpriv), GFP_KERNEL); if (unlikely(!fpriv)) { @@ -672,35 +672,39 @@ int radeon_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv) if (rdev->accel_working) { vm = &fpriv->vm; r = radeon_vm_init(rdev, vm); - if (r) { - kfree(fpriv); - goto out_suspend; - } + if (r) + goto out_fpriv; r = radeon_bo_reserve(rdev->ring_tmp_bo.bo, false); - if (r) { - radeon_vm_fini(rdev, vm); - kfree(fpriv); - goto out_suspend; - } + if (r) + goto out_vm_fini; /* map the ib pool buffer read only into * virtual address space */ vm->ib_bo_va = radeon_vm_bo_add(rdev, vm, rdev->ring_tmp_bo.bo); + if (!vm->ib_bo_va) { + r = -ENOMEM; + goto out_vm_fini; + } + r = radeon_vm_bo_set_addr(rdev, vm->ib_bo_va, RADEON_VA_IB_OFFSET, RADEON_VM_PAGE_READABLE | RADEON_VM_PAGE_SNOOPED); - if (r) { - radeon_vm_fini(rdev, vm); - kfree(fpriv); - goto out_suspend; - } + if (r) + goto out_vm_fini; } file_priv->driver_priv = fpriv; } + if (!r) + goto out_suspend; + +out_vm_fini: + radeon_vm_fini(rdev, vm); +out_fpriv: + kfree(fpriv); out_suspend: pm_runtime_mark_last_busy(dev->dev); pm_runtime_put_autosuspend(dev->dev); -- 2.34.1