Kees Cook 9e4bf6a08d block/rnbd-srv: Check for unlikely string overflow
Since "dev_search_path" can technically be as large as PATH_MAX,
there was a risk of truncation when copying it and a second string
into "full_path" since it was also PATH_MAX sized. The W=1 builds were
reporting this warning:

drivers/block/rnbd/rnbd-srv.c: In function 'process_msg_open.isra':
drivers/block/rnbd/rnbd-srv.c:616:51: warning: '%s' directive output may be truncated writing up to 254 bytes into a region of size between 0 and 4095 [-Wformat-truncation=]
  616 |                 snprintf(full_path, PATH_MAX, "%s/%s",
      |                                                   ^~
In function 'rnbd_srv_get_full_path',
    inlined from 'process_msg_open.isra' at drivers/block/rnbd/rnbd-srv.c:721:14: drivers/block/rnbd/rnbd-srv.c:616:17: note: 'snprintf' output between 2 and 4351 bytes into a destination of size 4096
  616 |                 snprintf(full_path, PATH_MAX, "%s/%s",
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  617 |                          dev_search_path, dev_name);
      |                          ~~~~~~~~~~~~~~~~~~~~~~~~~~

To fix this, unconditionally check for truncation (as was already done
for the case where "%SESSNAME%" was present).

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202312100355.lHoJPgKy-lkp@intel.com/
Cc: Md. Haris Iqbal <haris.iqbal@ionos.com>
Cc: Jack Wang <jinpu.wang@ionos.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc:  <linux-block@vger.kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20231212214738.work.169-kees@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-12-13 08:15:48 -07:00
2023-12-01 18:29:18 -07:00
2022-09-28 09:02:20 +02:00
2023-11-26 19:59:33 -08:00

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.
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