Commit 221fd753 authored Dec 17, 2011 by Kevin McKinney Committed by Greg Kroah-Hartman Dec 22, 2011

Staging: bcm: Fix an invalid dereference to a kmalloc in IOCTL_BCM_BULK_WRM



Variable IoBuffer.InputLength is chosen from userspace,
and can therefore be less than the intended size. In this
case,the memory from the kmalloc call is eventually cast
to a PBULKWRM_BUFFER. If the IoBuffer.InputLength does not
meet the minimum size of PBULKWRM_BUFFER, then we will get
a kernel Oops. To resolve this issue, this patch verifies
IoBuffer.InputLength meets the minimum size before invoking
the kmalloc call.

Signed-off-by: Kevin McKinney <klmckinney1@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

parent b72a7c85

drivers/staging/bcm/Bcmchar.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -1137,7 +1137,9 @@ cntrlEnd:
		if (copy_from_user(&IoBuffer, argp, sizeof(IOCTL_BUFFER)))
		return -EFAULT;

		/* FIXME: restrict length */
		if (IoBuffer.InputLength < sizeof(ULONG) * 2)
		return -EINVAL;

		pvBuffer = kmalloc(IoBuffer.InputLength, GFP_KERNEL);
		if (!pvBuffer)
		return -ENOMEM;