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authorKees Cook <keescook@chromium.org>2023-09-22 10:52:03 -0700
committerBartosz Golaszewski <bartosz.golaszewski@linaro.org>2023-09-25 09:42:23 +0200
commita512635da9f7223b97262a5f376c7f1c3e9f6f7d (patch)
tree199511367eed9a66098af079d821d766865f9422 /drivers/gpio/gpiolib-cdev.c
parent9f93f18305f5777820491e6ab9b34422c160371b (diff)
gpiolib: cdev: annotate struct linereq with __counted_by
Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). As found with Coccinelle[1], add __counted_by for struct linereq. Additionally, since the element count member must be set before accessing the annotated flexible array member, move its initialization earlier. [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Andy Shevchenko <andy@kernel.org> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Diffstat (limited to 'drivers/gpio/gpiolib-cdev.c')
-rw-r--r--drivers/gpio/gpiolib-cdev.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index e39d344feb28..31fc71a612c2 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -572,7 +572,7 @@ struct linereq {
DECLARE_KFIFO_PTR(events, struct gpio_v2_line_event);
atomic_t seqno;
struct mutex config_mutex;
- struct line lines[];
+ struct line lines[] __counted_by(num_lines);
};
#define GPIO_V2_LINE_BIAS_FLAGS \
@@ -1656,6 +1656,7 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip)
lr = kzalloc(struct_size(lr, lines, ulr.num_lines), GFP_KERNEL);
if (!lr)
return -ENOMEM;
+ lr->num_lines = ulr.num_lines;
lr->gdev = gpio_device_get(gdev);
@@ -1684,7 +1685,6 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip)
lr->event_buffer_size = GPIO_V2_LINES_MAX * 16;
atomic_set(&lr->seqno, 0);
- lr->num_lines = ulr.num_lines;
/* Request each GPIO */
for (i = 0; i < ulr.num_lines; i++) {