[patch 03/29] [S390] keyboard: integer underflow bug

From: Greg KH
Date: Thu Mar 10 2011 - 18:57:19 EST


2.6.37-stable review patch. If anyone has any objections, please let us know.

------------------

From: Dan Carpenter <error27@xxxxxxxxx>

commit b652277b09d3d030cb074cc6a98ba80b34244c03 upstream.

The "ct" variable should be an unsigned int. Both struct kbdiacrs
->kb_cnt and struct kbd_data ->accent_table_size are unsigned ints.

Making it signed causes a problem in KBDIACRUC because the user could
set the signed bit and cause a buffer overflow.

Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/s390/char/keyboard.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/s390/char/keyboard.c
+++ b/drivers/s390/char/keyboard.c
@@ -460,7 +460,8 @@ kbd_ioctl(struct kbd_data *kbd, struct f
unsigned int cmd, unsigned long arg)
{
void __user *argp;
- int ct, perm;
+ unsigned int ct;
+ int perm;

argp = (void __user *)arg;



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/