[PATCH 1/2] Staging: bcm: Add size minimum size restrictions for IOCTL_IDLE_REQ

Kevin McKinney klmckinney1 at gmail.com
Sun Sep 11 02:21:11 UTC 2011


>From b77facc21fccd909c204807767f4ddc05a10afdb Mon Sep 17 00:00:00 2001
From: Kevin McKinney <klmckinney1 at gmail.com>
Date: Sat, 3 Sep 2011 15:02:18 -0400
Subject: [PATCH 1/2] Staging: bcm: Add size minimum size restrictions for IOCTL_IDLE_REQ

If IoBuffer.InputLength is zero then this will cause an Oops when
we dereference the ZERO_SIZE_PTR.  Or if it's smaller than
sizeof(struct link_request) then we would get memory corruption
when we set ->PLength in CopyBufferToControlPacket()

Signed-off-by: Kevin McKinney <klmckinney1 at gmail.com>
---
 drivers/staging/bcm/Bcmchar.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/staging/bcm/Bcmchar.c b/drivers/staging/bcm/Bcmchar.c
index 6f8a75d..1905a83 100644
--- a/drivers/staging/bcm/Bcmchar.c
+++ b/drivers/staging/bcm/Bcmchar.c
@@ -687,7 +687,9 @@ static long bcm_char_ioctl(struct file *filp, UINT cmd, ULONG arg)
 		if (copy_from_user(&IoBuffer, argp, sizeof(IOCTL_BUFFER)))
 			return -EFAULT;
 
-		/* FIXME: don't accept any length from user */
+		if (IoBuffer.InputLength < sizeof(struct link_request))
+			return -EINVAL;
+
 		pvBuffer = kmalloc(IoBuffer.InputLength, GFP_KERNEL);
 		if (!pvBuffer)
 			return -ENOMEM;
-- 
1.7.4.1



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