From 51935d2259a476162bbf5c35ff81f3a01057ed6f Mon Sep 17 00:00:00 2001 From: Kevin McKinney Date: Tue, 8 Nov 2011 22:33:35 -0500 Subject: [PATCH] Staging: bcm: Clean up code in ioctl: IOCTL_BCM_EEPROM_REGISTER_READ This patch verifies two conditions before executing a kmalloc call. First, it checks to see that IoBuffer.OutputLength is not greater than an unsigned short. If so, an invalid value may be returned. The second change is a check to make sure IoBuffer.OutputLength is not equal to zero. Which simply keeps this code inline with the other ioctl, IOCTL_BCM_REGISTER_READ_PRIVATE. Signed-off-by: Kevin McKinney Signed-off-by: Greg Kroah-Hartman --- drivers/staging/bcm/Bcmchar.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/staging/bcm/Bcmchar.c b/drivers/staging/bcm/Bcmchar.c index e110d0e6887..7cffbddd5e9 100644 --- a/drivers/staging/bcm/Bcmchar.c +++ b/drivers/staging/bcm/Bcmchar.c @@ -306,7 +306,11 @@ static long bcm_char_ioctl(struct file *filp, UINT cmd, ULONG arg) if (copy_from_user(&sRdmBuffer, IoBuffer.InputBuffer, IoBuffer.InputLength)) return -EFAULT; - /* FIXME: don't trust user supplied length */ + if (IoBuffer.OutputLength > USHRT_MAX || + IoBuffer.OutputLength == 0) { + return -EINVAL; + } + temp_buff = kmalloc(IoBuffer.OutputLength, GFP_KERNEL); if (!temp_buff) return STATUS_FAILURE; -- 2.39.5