The 20 byte length of struct platform_device_id::name is not long enough
for many devices (especially regulators), where the string initialization
is getting truncated and missing the trailing NUL byte. This is seen
with GCC 15's -Wunterminated-string-initialization option:
drivers/regulator/hi6421v530-regulator.c:189:19: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (21 chars into 20 available) [-Wunterminated-string-initialization]
189 | { .name = "hi6421v530-regulator" },
| ^~~~~~~~~~~~~~~~~~~~~~
drivers/regulator/hi6421v600-regulator.c:278:19: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (21 chars into 20 available) [-Wunterminated-string-initialization]
278 | { .name = "hi6421v600-regulator" },
| ^~~~~~~~~~~~~~~~~~~~~~
drivers/regulator/lp87565-regulator.c:233:11: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (21 chars into 20 available) [-Wunterminated-string-initialization]
233 | { "lp87565-q1-regulator", },
| ^~~~~~~~~~~~~~~~~~~~~~
sound/soc/fsl/imx-pcm-rpmsg.c:818:19: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (21 chars into 20 available) [-Wunterminated-string-initialization]
818 | { .name = "rpmsg-micfil-channel" },
| ^~~~~~~~~~~~~~~~~~~~~~
drivers/iio/light/hid-sensor-als.c:457:25: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (21 chars into 20 available) [-Wunterminated-string-initialization]
457 | .name = "HID-SENSOR-LISS-0041",
| ^~~~~~~~~~~~~~~~~~~~~~
drivers/iio/light/hid-sensor-prox.c:366:25: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (21 chars into 20 available) [-Wunterminated-string-initialization]
366 | .name = "HID-SENSOR-LISS-0226",
| ^~~~~~~~~~~~~~~~~~~~~~
Increase the length to 24, slightly more than is currently being used by
the affected drivers. The string is used in '%s' format strings and via
the module code, which appears to do its own length encoding. This size
was chosen because there was already a 4 byte hole in the structure:
struct platform_device_id {
char name[20]; /* 0 20 */
/* XXX 4 bytes hole, try to pack */
kernel_ulong_t driver_data; /* 24 8 */
/* size: 32, cachelines: 1, members: 2 */
/* sum members: 28, holes: 1, sum holes: 4 */
/* last cacheline: 32 bytes */
};
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250415231420.work.066-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
655862865c