3.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Daniel Rosenberg <drosen@xxxxxxxxxx>
commit 717adfdaf14704fd3ec7fa2c04520c0723247eac upstream.
If our length is greater than the size of the buffer, we
overflow the buffer
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Daniel Rosenberg <drosen@xxxxxxxxxx>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/hid/hid-debug.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
--- a/drivers/hid/hid-debug.c
+++ b/drivers/hid/hid-debug.c
@@ -1150,6 +1150,8 @@ copy_rest:
goto out;
if (list->tail > list->head) {
len = list->tail - list->head;
+ if (len > count)
+ len = count;
if (copy_to_user(buffer + ret, &list->hid_debug_buf[list->head], len)) {
ret = -EFAULT;
@@ -1159,6 +1161,8 @@ copy_rest:
list->head += len;
} else {
len = HID_DEBUG_BUFSIZE - list->head;
+ if (len > count)
+ len = count;
if (copy_to_user(buffer, &list->hid_debug_buf[list->head], len)) {
ret = -EFAULT;
@@ -1166,7 +1170,9 @@ copy_rest:
}
list->head = 0;
ret += len;
- goto copy_rest;
+ count -= len;
+ if (count > 0)
+ goto copy_rest;
}
}
