Staging: bcm: Fix an integer overflow in IOCTL_BCM_NVM_READ/WRITE
Variables stNVMReadWrite.uioffset and stNVMReadWrite.uiNumBytes
are chosen from userspace and can be very high. The sum of
these two digits would result in a small number. Therefore,
this patch verifies a negative number was not entered, and
reorganizes the equation to remove the integer overflow.
Signed-off-by: Kevin McKinney <klmckinney1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/bcm/Bcmchar.c b/drivers/staging/bcm/Bcmchar.c
index 179707b..8bf3f57 100644
--- a/drivers/staging/bcm/Bcmchar.c
+++ b/drivers/staging/bcm/Bcmchar.c
@@ -1302,8 +1302,10 @@
/*
* Deny the access if the offset crosses the cal area limit.
*/
+ if (stNVMReadWrite.uiNumBytes > Adapter->uiNVMDSDSize)
+ return STATUS_FAILURE;
- if ((stNVMReadWrite.uiOffset + stNVMReadWrite.uiNumBytes) > Adapter->uiNVMDSDSize) {
+ if (stNVMReadWrite.uiOffset > Adapter->uiNVMDSDSize - stNVMReadWrite.uiNumBytes) {
/* BCM_DEBUG_PRINT(Adapter,DBG_TYPE_PRINTK, 0, 0,"Can't allow access beyond NVM Size: 0x%x 0x%x\n", stNVMReadWrite.uiOffset, stNVMReadWrite.uiNumBytes); */
return STATUS_FAILURE;
}