[34-longterm 147/247] usb: iowarrior: don't trust report_size for buffer size

From: Paul Gortmaker
Date: Thu Jun 23 2011 - 14:05:01 EST

From: Kees Cook <kees.cook@xxxxxxxxxxxxx>

This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.

commit 3ed780117dbe5acb64280d218f0347f238dafed0 upstream.

If the iowarrior devices in this case statement support more than 8 bytes
per report, it is possible to write past the end of a kernel heap allocation.
This will probably never be possible, but change the allocation to be more
defensive anyway.

Signed-off-by: Kees Cook <kees.cook@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
drivers/usb/misc/iowarrior.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/usb/misc/iowarrior.c b/drivers/usb/misc/iowarrior.c
index 7c84321..f2a4ad5 100644
--- a/drivers/usb/misc/iowarrior.c
+++ b/drivers/usb/misc/iowarrior.c
@@ -373,7 +373,7 @@ static ssize_t iowarrior_write(struct file *file,
/* IOW24 and IOW40 use a synchronous call */
- buf = kmalloc(8, GFP_KERNEL); /* 8 bytes are enough for both products */
+ buf = kmalloc(count, GFP_KERNEL);
if (!buf) {
retval = -ENOMEM;
goto exit;

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