Messages in this thread | | | Subject | Re: [PATCH] drivers: of: check input parameter name for __of_find_property | From | Rob Herring <> | Date | Tue, 15 Sep 2015 21:27:59 -0500 |
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On 09/15/2015 07:16 PM, Peng Fan wrote: > Hi Rob, > > On Tue, Sep 15, 2015 at 10:56:28AM -0500, Rob Herring wrote: >> On 09/11/2015 08:44 AM, Peng Fan wrote: >>> Check input parameter 'name' for __of_find_property. If name is NULL, >>> of_prop_cmp->strcasecmp may trigger panic. >> >> Arguably that could be a feature. Do you have a usecase where name being >> NULL is valid and panicking is a problem? > > In drivers/pinctrl/devicetree.c > > 195 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state); > 196 prop = of_find_property(np, propname, &size); > 197 kfree(propname); > 198 if (!prop) > 199 break; > > If propname is NULL, of_find_property may trigger panic. Anyway propname should be checked > before passing to of_find_property.
propname will only be NULL if the memory allocation failed which gives you a big warning message. I don't think you would want to continue on in this case.
So I'm inclined to leave this as is with passing NULL to of_find_property to always be an error and fatal.
Rob
> I did not met panic message. I wrote this patch when I was reading the piece code. > I think the name parameter should be checked before doing string compare. > > Regards, > Peng. > >> >> Rob >> >>> >>> Signed-off-by: Peng Fan <van.freenix@gmail.com> >>> Cc: Rob Herring <robh+dt@kernel.org> >>> Cc: Frank Rowand <frowand.list@gmail.com> >>> Cc: Grant Likely <grant.likely@linaro.org> >>> --- >>> drivers/of/base.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/of/base.c b/drivers/of/base.c >>> index 8b5a187..e41436d 100644 >>> --- a/drivers/of/base.c >>> +++ b/drivers/of/base.c >>> @@ -215,7 +215,7 @@ static struct property *__of_find_property(const struct device_node *np, >>> { >>> struct property *pp; >>> >>> - if (!np) >>> + if (!np || !name) >>> return NULL; >>> >>> for (pp = np->properties; pp; pp = pp->next) { >>> >>
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