lkml.org 
[lkml]   [2014]   [Sep]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] resource: Add NULL check in next_resource
Date
Commit 8c86e70acead ("resource: provide new functions to walk through
resources") adds a suble new requirement that iomem_resource.child must
not be NULL when walk_system_ram_range is called. This can cause a crash
if it turns out that there are no children. The crash ('Unable to handle
kernel NULL pointer dereference') is seen when trying to test a crisv32
image on kernels with this commit applied.

Fix by adding a NULL check into next_resource().

Fixes: 8c86e70acead ("resource: provide new functions to walk through resources")
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
The NULL check could be added elsewhere instead. I am open to suggestions.

kernel/resource.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/kernel/resource.c b/kernel/resource.c
index 60c5a38..00c57ad 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -61,6 +61,9 @@ static DEFINE_SPINLOCK(bootmem_resource_lock);

static struct resource *next_resource(struct resource *p, bool sibling_only)
{
+ if (p == NULL)
+ return NULL;
+
/* Caller wants to traverse through siblings only */
if (sibling_only)
return p->sibling;
--
1.9.1


\
 
 \ /
  Last update: 2014-09-21 18:21    [W:0.067 / U:0.504 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site