This is a note to let you know that I've just added the patch titled
kfifo: fix kfifo_to_user() return type
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kfifo-fix-kfifo_to_user-return-type.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 7bedd98f87c5aa8d77d26ef0f53ea3368c0b681b
Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Date: Fri Jun 24 08:30:04 2022 +0300
kfifo: fix kfifo_to_user() return type
[ Upstream commit 045ed31e23aea840648c290dbde04797064960db ]
The kfifo_to_user() macro is supposed to return zero for success or
negative error codes. Unfortunately, there is a signedness bug so it
returns unsigned int. This only affects callers which try to save the
result in ssize_t and as far as I can see the only place which does that
is line6_hwdep_read().
TL;DR: s/_uint/_int/.
Link: https://lkml.kernel.org/r/YrVL3OJVLlNhIMFs@kili
Fixes: 144ecf310eb5 ("kfifo: fix kfifo_alloc() to return a signed int value")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: Stefani Seibold <stefani@xxxxxxxxxxx>
Cc: Randy Dunlap <randy.dunlap@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/linux/kfifo.h b/include/linux/kfifo.h
index 41eb6fdf87a8..c17b63b0d269 100644
--- a/include/linux/kfifo.h
+++ b/include/linux/kfifo.h
@@ -628,7 +628,7 @@ __kfifo_uint_must_check_helper( \
* writer, you don't need extra locking to use these macro.
*/
#define kfifo_to_user(fifo, to, len, copied) \
-__kfifo_uint_must_check_helper( \
+__kfifo_int_must_check_helper( \
({ \
typeof((fifo) + 1) __tmp = (fifo); \
void __user *__to = (to); \
