HID: hidraw: fix a problem of memory leak in hidraw_release()

[ Upstream commit a3bdcdd022c68942a774e8e63424cc11c85aab78 ]

'struct hidraw_list' is a circular queue whose head can be smaller than
tail. Using 'list->tail != list->head' to release all memory that should
be released.

Fixes: a5623a203cff ("HID: hidraw: fix memory leak in hidraw_release()")
Signed-off-by: Su Hui <suhui@nfschina.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
index 13c8dd8..2bc762d 100644 (file)
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -357,8 +357,11 @@ static int hidraw_release(struct inode * inode, struct file * file)
        down_write(&minors_rwsem);
 
        spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
-       for (int i = list->tail; i < list->head; i++)
-               kfree(list->buffer[i].value);
+       while (list->tail != list->head) {
+               kfree(list->buffer[list->tail].value);
+               list->buffer[list->tail].value = NULL;
+               list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
+       }
        list_del(&list->node);
        spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
        kfree(list);