Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 14/74] gpio: fix line flag validation in linehandle_create | Date | Fri, 20 Sep 2019 00:03:27 +0200 |
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From: Kent Gibson <warthog618@gmail.com>
commit e95fbc130a162ba9ad956311b95aa0da269eea48 upstream.
linehandle_create should not allow both GPIOHANDLE_REQUEST_INPUT and GPIOHANDLE_REQUEST_OUTPUT to be set.
Fixes: d7c51b47ac11 ("gpio: userspace ABI for reading/writing GPIO lines") Cc: stable <stable@vger.kernel.org> Signed-off-by: Kent Gibson <warthog618@gmail.com> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/gpio/gpiolib.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
--- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -426,12 +426,23 @@ static int linehandle_create(struct gpio struct linehandle_state *lh; struct file *file; int fd, i, count = 0, ret; + u32 lflags; if (copy_from_user(&handlereq, ip, sizeof(handlereq))) return -EFAULT; if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX)) return -EINVAL; + lflags = handlereq.flags; + + /* + * Do not allow both INPUT & OUTPUT flags to be set as they are + * contradictory. + */ + if ((lflags & GPIOHANDLE_REQUEST_INPUT) && + (lflags & GPIOHANDLE_REQUEST_OUTPUT)) + return -EINVAL; + lh = kzalloc(sizeof(*lh), GFP_KERNEL); if (!lh) return -ENOMEM; @@ -452,7 +463,6 @@ static int linehandle_create(struct gpio /* Request each GPIO */ for (i = 0; i < handlereq.lines; i++) { u32 offset = handlereq.lineoffsets[i]; - u32 lflags = handlereq.flags; struct gpio_desc *desc; if (offset >= gdev->ngpio) {
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