[PATCH v2] gpu: vga: limit kmalloc'ed memory size

From: Vasiliy Kulikov
Date: Mon Nov 22 2010 - 13:03:44 EST


count is not checked before kmalloc() call. Too big value would
generate stack dump. To prevent this limit 'count' maximum value.
1024 looks OK - the data should be the string of tens of bytes.

Signed-off-by: Vasiliy Kulikov <segoon@xxxxxxxxxxxx>
---
Compile tested only.

v1 had incorrect comment text, as Dan Rosenberg noticed.

drivers/gpu/vga/vgaarb.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
index c380c65..09e3090 100644
--- a/drivers/gpu/vga/vgaarb.c
+++ b/drivers/gpu/vga/vgaarb.c
@@ -836,6 +836,8 @@ static ssize_t vga_arb_write(struct file *file, const char __user * buf,
int ret_val;
int i;

+ if (count > 1024)
+ count = 1024;

kbuf = kmalloc(count + 1, GFP_KERNEL);
if (!kbuf)
--
1.7.0.4

--
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/