From mboxrd@z Thu Jan 1 00:00:00 1970 From: Masami Hiramatsu Subject: Re: [PATCH v2] [BUGFIX] gpio: reject invalid gpio before getting gpio_desc Date: Tue, 1 Aug 2017 17:35:50 +0900 Message-ID: <20170801173550.4e63ceaa562d8e81ecfb1a25@kernel.org> References: <150146625669.11567.9576692487524672090.stgit@devbox> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Linus Walleij Cc: "linux-gpio@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Andy Shevchenko , Masahiro Yamada , Masami Hiramatsu , Jassi Brar List-Id: linux-gpio@vger.kernel.org On Tue, 1 Aug 2017 10:09:09 +0200 Linus Walleij wrote: > On Mon, Jul 31, 2017 at 3:57 AM, Masami Hiramatsu wrote: > > > Check user-given gpio number and reject it before > > calling gpio_to_desc() because gpio_to_desc() is > > for kernel driver and it expects given gpio number > > is valid (means 0 to 511). > > If given number is invalid, gpio_to_desc() calls > > WARN() and dump registers and stack for debug. > > This means user can easily kick WARN() just by > > writing invalid gpio number (e.g. 512) to > > /sys/class/gpio/export. > > > > Fixes: 0e9a5edf5d01 ("gpio: fix deferred probe detection for legacy API") > > Signed-off-by: Masami Hiramatsu > > --- > > Changes in v2: > > - Add gpio_to_valid_desc() according to Andy's comment (Thanks!). > > - Fix patch description. > > I hate the old sysfs ABI sigh. Thanks for fixing it anyways! > > Should this be tagged for stable? Yes, I think so. Since this has been introduced 3 years ago, it would be nice to go to older stable trees too. Thanks, > > Waiting for Andy's review before applying. > > Yours, > Linus Walleij -- Masami Hiramatsu