From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Subject: [patch] gdth: integer overflow in ioctl Date: Fri, 8 Oct 2010 09:03:07 +0200 Message-ID: <20101008070307.GF11681@bicker> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: Achim Leubner Cc: "James E.J. Bottomley" , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org List-Id: linux-scsi@vger.kernel.org gdth_ioctl_alloc() takes the size variable as an int. copy_from_user() takes the size variable as an unsigned long. gen.data_len and gen.sense_len are unsigned longs. On x86_64 longs are 64 bit and ints are 32 bit. We could pass in a very large number and the allocation would truncate the size to 32 bits and allocate a small buffer. Then when we do the copy_from_user(), it would result in a memory corruption. CC: stable@kernel.org Signed-off-by: Dan Carpenter diff --git a/drivers/scsi/gdth.c b/drivers/scsi/gdth.c index b860d65..4cf7ffa 100644 --- a/drivers/scsi/gdth.c +++ b/drivers/scsi/gdth.c @@ -4175,6 +4175,14 @@ static int ioc_general(void __user *arg, char *cmnd) ha = gdth_find_ha(gen.ionode); if (!ha) return -EFAULT; + + if (gen.data_len > INT_MAX) + return -EINVAL; + if (gen.sense_len > INT_MAX) + return -EINVAL; + if (gen.data_len + gen.sense_len > INT_MAX) + return -EINVAL; + if (gen.data_len + gen.sense_len != 0) { if (!(buf = gdth_ioctl_alloc(ha, gen.data_len + gen.sense_len, FALSE, &paddr)))