Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753274AbaJAQD3 (ORCPT ); Wed, 1 Oct 2014 12:03:29 -0400 Received: from mail-wi0-f171.google.com ([209.85.212.171]:36739 "EHLO mail-wi0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751419AbaJAQD1 (ORCPT ); Wed, 1 Oct 2014 12:03:27 -0400 From: Grant Likely To: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Cc: Grant Likely , Gaurav Minocha Subject: [PATCH] of: Fix NULL dereference in selftest removal code Date: Wed, 1 Oct 2014 17:02:51 +0100 Message-Id: <1412179371-4053-1-git-send-email-grant.likely@linaro.org> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The selftest code removes its testcase data from the live tree when exiting, but if the testcases data tree contains an empty child of the root, then it causes an oops due to a NULL dereference. The reason is that the code tries to directly dereference the child pointer without checking first if a child is actually there. The solution is to pass the parent node into detach_node_and_children() instead of trying to pass the child. This required removing the code that attempts to remove all of the sibling nodes in detach_node_and_children(), which was never sensible in the first place. At the same time add a check to make sure the bounds of the nodes list are not exceeded by the testdata tree. If they are then abort. Signed-off-by: Grant Likely Cc: Gaurav Minocha --- drivers/of/selftest.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/of/selftest.c b/drivers/of/selftest.c index a737cb5974de..883e60b04eb5 100644 --- a/drivers/of/selftest.c +++ b/drivers/of/selftest.c @@ -637,6 +637,8 @@ static int attach_node_and_children(struct device_node *np) dup = np; while (dup) { + if (WARN_ON(last_node_index >= NO_OF_NODES)) + return -EINVAL; nodes[last_node_index++] = dup; dup = dup->sibling; } @@ -717,10 +719,6 @@ static void detach_node_and_children(struct device_node *np) { while (np->child) detach_node_and_children(np->child); - - while (np->sibling) - detach_node_and_children(np->sibling); - of_detach_node(np); } @@ -749,8 +747,7 @@ static void selftest_data_remove(void) if (nodes[last_node_index]) { np = of_find_node_by_path(nodes[last_node_index]->full_name); if (strcmp(np->full_name, "/aliases") != 0) { - detach_node_and_children(np->child); - of_detach_node(np); + detach_node_and_children(np); } else { for_each_property_of_node(np, prop) { if (strcmp(prop->name, "testcase-alias") == 0) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/