From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH] drivers: of: check input parameter name for __of_find_property Date: Tue, 15 Sep 2015 21:27:59 -0500 Message-ID: <55F8D3AF.9070503@kernel.org> References: <1441979043-19694-1-git-send-email-van.freenix@gmail.com> <55F83FAC.5080002@kernel.org> <20150916001650.GA28082@linux-4gyl.site> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150916001650.GA28082-12w76u+6CWdQVMFFLWfSwA@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Peng Fan Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Frank Rowand , Grant Likely List-Id: devicetree@vger.kernel.org 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 >>> Cc: Rob Herring >>> Cc: Frank Rowand >>> Cc: Grant Likely >>> --- >>> 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) { >>> >> -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html