Glenn Washburn 980cffdbb0 cryptodisk: Fix Coverity use after free bug
The Coverity output is:

  *** CID 366905:  Memory - illegal accesses  (USE_AFTER_FREE)
  /grub-core/disk/cryptodisk.c: 1064 in grub_cryptodisk_scan_device_real()
  1058      cleanup:
  1059       if (askpass)
  1060         {
  1061           cargs->key_len = 0;
  1062           grub_free (cargs->key_data);
  1063         }
  >>>     CID 366905:  Memory - illegal accesses  (USE_AFTER_FREE)
  >>>     Using freed pointer "dev".
  1064       return dev;
  1065     }
  1066
  1067     #ifdef GRUB_UTIL
  1068     #include <grub/util/misc.h>
  1069     grub_err_t

Here the "dev" variable can point to a freed cryptodisk device if the
function grub_cryptodisk_insert() fails. This can happen only on a OOM
condition, but when this happens grub_cryptodisk_insert() calls grub_free on
the passed device. Since grub_cryptodisk_scan_device_real() assumes that
grub_cryptodisk_insert() is always successful, it will return the device,
though the device was freed.

Change grub_cryptodisk_insert() to not free the passed device on failure.
Then on grub_cryptodisk_insert() failure, free the device pointer. This is
done by going to the label "error", which will call cryptodisk_close() to
free the device and set the device pointer to NULL, so that a pointer to
freed memory is not returned.

Fixes: CID 366905

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2022-02-07 20:15:26 +01:00
2012-02-23 17:21:38 +01:00
2020-09-18 22:31:30 +02:00
2021-09-06 17:00:53 +02:00
2021-09-06 16:31:38 +02:00
2011-01-11 00:06:01 +01:00
2015-03-03 20:50:37 +01:00
2013-11-20 00:52:23 +01:00
2017-02-04 00:06:57 +01:00
2021-06-08 14:24:34 +02:00
2021-06-08 16:28:15 +02:00
2021-06-08 14:24:34 +02:00
2021-06-08 14:24:34 +02:00
2016-02-12 17:51:52 +01:00

This is GRUB 2, the second version of the GRand Unified Bootloader.
GRUB 2 is rewritten from scratch to make GNU GRUB cleaner, safer, more
robust, more powerful, and more portable.

See the file NEWS for a description of recent changes to GRUB 2.

See the file INSTALL for instructions on how to build and install the
GRUB 2 data and program files.

See the file MAINTAINERS for information about the GRUB maintainers, etc.

If you found a security vulnerability in the GRUB please check the SECURITY
file to get more information how to properly report this kind of bugs to
the maintainers.

Please visit the official web page of GRUB 2, for more information.
The URL is <http://www.gnu.org/software/grub/grub.html>.

More extensive documentation is available in the Info manual,
accessible using 'info grub' after building and installing GRUB 2.

There are a number of important user-visible differences from the
first version of GRUB, now known as GRUB Legacy. For a summary, please
see:

  info grub Introduction 'Changes from GRUB Legacy'
Description
No description provided
Readme
Languages
C 82.5%
Assembly 13.6%
M4 1.4%
Shell 1.3%
Makefile 0.5%
Other 0.5%