Messages in this thread Patch in this message | | | From | Guenter Roeck <> | Subject | [PATCH] resource: Add NULL check in next_resource | Date | Sun, 21 Sep 2014 08:51:44 -0700 |
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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
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