From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jia-Ju Bai Subject: [PATCH v2] input: touchscreen: wm97xx-core: Fix possible null-pointer dereferences in wm97xx_ts_input_open() Date: Fri, 26 Jul 2019 17:14:36 +0800 Message-ID: <20190726091436.8866-1-baijiaju1990@gmail.com> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: dmitry.torokhov@gmail.com, tglx@linutronix.de, gregkh@linuxfoundation.org, allison@lohutok.net, rdunlap@infradead.org Cc: patches@opensource.cirrus.com, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai List-Id: linux-input@vger.kernel.org In wm97xx_ts_input_open(), there is an if statement on line 507 to check whether wm->mach_ops is NULL: if (wm->mach_ops && wm->mach_ops->acc_enabled) When wm->mach_ops is NULL, it is used on line 521: wm97xx_init_pen_irq(wm); BUG_ON(!wm->mach_ops->irq_enable); BUG_ON(!wm->mach_ops->irq_gpio); wm97xx_reg_write(..., reg & ~(wm->mach_ops->irq_gpio)) Thus, possible null-pointer dereferences may occur. To fix these bugs, wm->mach_ops is checked at the beginning of wm97xx_init_pen_irq(). These bugs found by a static analysis tool STCheck written by us. Signed-off-by: Jia-Ju Bai --- v2: * Add a new check of wm->mach_ops in wm97xx_init_pen_irq(). Thank Charles for helpful advice. --- drivers/input/touchscreen/wm97xx-core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/input/touchscreen/wm97xx-core.c b/drivers/input/touchscreen/wm97xx-core.c index 0a174bd82915..50b016abf492 100644 --- a/drivers/input/touchscreen/wm97xx-core.c +++ b/drivers/input/touchscreen/wm97xx-core.c @@ -374,6 +374,9 @@ static int wm97xx_init_pen_irq(struct wm97xx *wm) { u16 reg; + if (!wm->mach_ops) + return -EINVAL; + /* If an interrupt is supplied an IRQ enable operation must also be * provided. */ BUG_ON(!wm->mach_ops->irq_enable); -- 2.17.0