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[194.223.74.160]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-5b8b57897dfsm1951402e87.3.2026.09.17.08.03.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Sep 2026 08:03:16 -0700 (PDT) Date: Thu, 17 Sep 2026 23:03:06 +0800 From: Kent Gibson To: Bartosz Golaszewski Cc: Bartosz Golaszewski , Linus Walleij , Andy Shevchenko , linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Sashiko Subject: Re: [PATCH] gpio: cdev: fix kernel stack leak to user-space in error path Message-ID: <20260917150306.GA131235@rigel> References: <20260917-gpio-cdev-stack-leak-fixes-v1-1-2bb52879e49c@oss.qualcomm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260917-gpio-cdev-stack-leak-fixes-v1-1-2bb52879e49c@oss.qualcomm.com> On Thu, Sep 17, 2026 at 04:39:05PM +0200, Bartosz Golaszewski wrote: > If we fail to acquire the GPIO chip guard in gpio_desc_to_lineinfo(), we > return immediately before zeroing the info struct we'll end up passing > to the user-space later in lineinfo_get_v1(). This may leak the kernel > stack contents. Move the memset() before trying to acquire the SRCU read > lock. > > Fixes: d83cee3d2bb1 ("gpio: protect the pointer to gpio_chip in gpio_device with SRCU") > Cc: stable@vger.kernel.org > Reported-by: Sashiko > Closes: https://sashiko.dev/#/patchset/20260912123529.7951-1-tzungbi%40kernel.org?part=3 > Signed-off-by: Bartosz Golaszewski Reviewed-by: Kent Gibson Cheers, Kent.