printk: kunit: Fix __counted_by() in struct prbtest_rbdata

__counted_by() has to point to a variable which defines the size
of the related array. The code must never access the array
beyond this limit.

struct prbtest_rbdata currently stores the length of the string.
And the code access the array beyond the limit when writing
or reading the trailing '\0'.

Store the size of the string, including the trailing '\0' if
we wanted to keep __counted_by().

Consistently use "_size" suffix when the trailing '\0' is counted.
Note that MAX_RBDATA_TEXT_SIZE was originally used to limit
the text length.

When touching the code, make sure that @text_size produced by
get_random_u32_inclusive() stays within the limits.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/eaea66b9-266a-46e7-980d-33f40ad4b215@sabinyo.mountain
Suggested-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://patch.msgid.link/20250702095157.110916-4-pmladek@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>

0 files changed, 0 insertions, 0 deletions