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authorArnd Bergmann <arnd@arndb.de>2016-06-16 11:02:41 +0200
committerLinus Walleij <linus.walleij@linaro.org>2016-06-16 12:00:25 +0200
commitbc0207a5461169eba13e9421bd7632399b72e3ab (patch)
tree53681e9334bb0a60fae868cef60b2be714d01336 /drivers/gpio
parent97f69747d8b11c76df321894344beeae6bafc301 (diff)
downloadlinux-bc0207a5461169eba13e9421bd7632399b72e3ab.tar.bz2
gpiolib: avoid uninitialized data in gpio kfifo
gcc reports a theoretical case for returning uninitialized data in the kfifo when a GPIO interrupt happens and neither GPIOEVENT_REQUEST_RISING_EDGE nor GPIOEVENT_REQUEST_FALLING_EDGE are set: drivers/gpio/gpiolib.c: In function 'lineevent_irq_thread': drivers/gpio/gpiolib.c:683:87: error: 'ge.id' may be used uninitialized in this function [-Werror=maybe-uninitialized] This case should not happen, but to be on the safe side, let's return from the irq handler without adding data to the FIFO to ensure we can never leak stack data to user space. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 61f922db7221 ("gpio: userspace ABI for reading GPIO line events") Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/gpiolib.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 5239230ad075..c826844abdeb 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -674,6 +674,8 @@ irqreturn_t lineevent_irq_thread(int irq, void *p)
} else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
/* Emit high-to-low event */
ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
+ } else {
+ return IRQ_NONE;
}
ret = kfifo_put(&le->events, ge);