tree 7ead0857a87874bb3362953d5fb55749f88903de
parent 66f75a5d028beaf67c931435fdc3e7823125730c
author Will Newton <will.newton@gmail.com> 1333104662 +0100
committer David Woodhouse <David.Woodhouse@intel.com> 1336418990 +0100

mtd: fix oops in dataflash driver

I'm seeing an oops in mtd_dataflash.c with Linux 3.3. What appears to
be happening is that otp_select_filemode calls mtd_read_fact_prot_reg
with -1 for offset and length and a NULL buffer to test if OTP
operations are supported. This finds its way down to otp_read in
mtd_dataflash.c and causes an oops when memcpying the returned data
into the NULL buf.

None of the checks in otp_read catches the negative length and offset.
Changing the length of the dummy read to 0 prevents the oops.

Cc: stable@kernel.org [3.3+]
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>