[PATCH] driver core: Check if r->name is valid in platform_get_resource_byname()

From: Peter Ujfalusi
Date: Thu Aug 23 2012 - 10:10:26 EST


Safety check for the validity of the resource name before calling strcmp().
If the resource name is NULL do not compare it, just skip it.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
---

Hi Greg,

I have experienced with a kernel crash because the r->name was NULL when booting
OMAP4+ kernel with devicetree.
I have sent a separate patch for the OMAP specific root (with analysis of the
issue):
http://marc.info/?l=linux-omap&m=134573006327647&w=2

I agree that it is unlikely to have the name NULL, but I think it does not hurt
if we do a safety check before comparing the strings.

Best Regards,
Peter

drivers/base/platform.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index a1a7225..d717c2b 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -99,6 +99,9 @@ struct resource *platform_get_resource_byname(struct platform_device *dev,
for (i = 0; i < dev->num_resources; i++) {
struct resource *r = &dev->resource[i];

+ if (unlikely(!r->name))
+ continue;
+
if (type == resource_type(r) && !strcmp(r->name, name))
return r;
}
--
1.7.8.6

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