Messages in this thread Patch in this message | | | From | Len Baker <> | Subject | [PATCH] Input: omap-keypad - prefer struct_size over open coded arithmetic | Date | Sat, 11 Sep 2021 13:27:16 +0200 |
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As noted in the "Deprecated Interfaces, Language Features, Attributes, and Conventions" documentation [1], size calculations (especially multiplication) should not be performed in memory allocator (or similar) function arguments due to the risk of them overflowing. This could lead to values wrapping around and a smaller allocation being made than the caller was expecting. Using those allocations could lead to linear overflows of heap memory and other misbehaviors.
So, use the struct_size() helper to do the arithmetic instead of the argument "size + count * size" in the kzalloc() function.
[1] https://www.kernel.org/doc/html/v5.14/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
Signed-off-by: Len Baker <len.baker@gmx.com> --- drivers/input/keyboard/omap-keypad.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/input/keyboard/omap-keypad.c b/drivers/input/keyboard/omap-keypad.c index dbe836c7ff47..eb3a687796e7 100644 --- a/drivers/input/keyboard/omap-keypad.c +++ b/drivers/input/keyboard/omap-keypad.c @@ -190,8 +190,7 @@ static int omap_kp_probe(struct platform_device *pdev) row_shift = get_count_order(pdata->cols); keycodemax = pdata->rows << row_shift;
- omap_kp = kzalloc(sizeof(struct omap_kp) + - keycodemax * sizeof(unsigned short), GFP_KERNEL); + omap_kp = kzalloc(struct_size(omap_kp, keymap, keycodemax), GFP_KERNEL); input_dev = input_allocate_device(); if (!omap_kp || !input_dev) { kfree(omap_kp); -- 2.25.1
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