73d7b06e90
Commit 0fbb4d93b38b ("dm: add dm_submit_bio_remap interface") changed
the alloc_io() function to delay the initialization of struct dm_io's
orig_bio member, leaving it NULL until after the dm_io and associated
user submitted bio is processed by __split_and_process_bio(). This
change causes a NULL pointer dereference in dm_zone_map_bio() when the
original user bio is inspected to detect the need for zone append
command emulation.
Fix this NULL pointer by updating dm_zone_map_bio() to not access
->orig_bio when the same info can be accessed from the clone of the
->orig_bio _before_ any ->map processing. Save off the bio_op() and
bio_sectors() for the clone and then use the saved orig_bio_details as
needed.
Fixes: 0fbb4d93b38b ("dm: add dm_submit_bio_remap interface")
Reported-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.