Re: [PATCH stable v2 1/2] termios, tty/tty_baudrate.c: fix buffer overrun

[hpa]

On October 23, 2018 7:53:51 AM PDT, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>On Mon, Oct 22, 2018 at 09:19:04AM -0700, H. Peter Anvin (Intel) wrote:
>> From: "H. Peter Anvin" <hpa@xxxxxxxxx>
>> 
>> On architectures with CBAUDEX == 0 (Alpha and PowerPC), the code in
>tty_baudrate.c does
>> not do any limit checking on the tty_baudrate[] array, and in fact a
>> buffer overrun is possible on both architectures. Add a limit check
>to
>> prevent that situation.
>> 
>> This will be followed by a much bigger cleanup/simplification patch.
>> 
>> Signed-off-by: H. Peter Anvin (Intel) <hpa@xxxxxxxxx>
>> Requested-by: Cc: Johan Hovold <johan@xxxxxxxxxx>
>> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>> Cc: Jiri Slaby <jslaby@xxxxxxxx>
>> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
>> Cc: Richard Henderson <rth@xxxxxxxxxxx>
>> Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx>
>> Cc: Matt Turner <mattst88@xxxxxxxxx>
>> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>> Cc: Kate Stewart <kstewart@xxxxxxxxxxxxxxxxxxx>
>> Cc: Philippe Ombredanne <pombredanne@xxxxxxxx>
>> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>> Cc: Eugene Syromiatnikov <esyr@xxxxxxxxxx>
>> Cc: <linux-alpha@xxxxxxxxxxxxxxx>
>> Cc: <linux-serial@xxxxxxxxxxxxxxx>
>> Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
>> Cc: <stable@xxxxxxxxxxxxxxx>
>> ---
>>  drivers/tty/tty_baudrate.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>
>As I think Al's big termios cleanups are going to be hitting Linus's
>tree soon, do you know how these patches interact with that?
>
>This patch seems like it will not, so I'll be glad to queue that up
>after my first round of patches get merged to Linus later this week,
>but
>the second one worries me.
>
>thanks,
>
>greg k-h

I have been working with Al; we had approached much the same problems but from different directions. Mine ended up being a bit more comprehensive as a result, so I think we're going to end up using my code with Al's reviews.

So bottom line is that it should be all good.
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