Re: KASAN + general protection fault while writing to mmc

[Linus Walleij]

On Thu, Aug 10, 2017 at 10:07 PM, Seraphime Kirkovski
<kirkseraph@xxxxxxxxx> wrote:

> I got this while restoring a backup with dd on an SDCard.
> On 4.13.0-rc4 I get it everytime.
>
> I'm not sure if it isn't a hardware problem as I have no more cards
> left.

The only patch that touched blk_rq_map_sg() that calls sg_next()
was this:

commit 67e69d5220c904238f94bb2e6001d7c590f5a0bb
Author: Linus Walleij <linus.walleij@xxxxxxxxxx>
Date:   Fri May 19 15:37:27 2017 +0200

    mmc: block: remove req back pointer

    Just as we can use blk_mq_rq_from_pdu() to get the per-request
    tag we can use blk_mq_rq_to_pdu() to get a request from a tag.
    Introduce a static inline helper so we are on the clear what
    is happening.

    Suggested-by: Christoph Hellwig <hch@xxxxxx>
    Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
    Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>

Can you try reverting it and see if the problem goes away?

Yours,
Linus Walleij