[Qemu-commits] [qemu/qemu] b83b40: vfio/pci: Fix a use-after-free issue

[Richard Henderson]

  Branch: refs/heads/staging
  Home:   https://github.com/qemu/qemu
  Commit: b83b40b614846b86e69f1680aec379594dc77d6b
      
https://github.com/qemu/qemu/commit/b83b40b614846b86e69f1680aec379594dc77d6b
  Author: Zhenzhong Duan <zhenzhong.duan@intel.com>
  Date:   2023-05-24 (Wed, 24 May 2023)

  Changed paths:
    M hw/vfio/pci.c

  Log Message:
  -----------
  vfio/pci: Fix a use-after-free issue

vbasedev->name is freed wrongly which leads to garbage VFIO trace log.
Fix it by allocating a dup of vbasedev->name and then free the dup.

Fixes: 2dca1b37a760 ("vfio/pci: add support for VF token")
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Cédric Le Goater <clg@redhat.com>


  Commit: dbdea0dbfe2cef9ef6c752e9077e4fc98724194c
      
https://github.com/qemu/qemu/commit/dbdea0dbfe2cef9ef6c752e9077e4fc98724194c
  Author: Akihiko Odaki <akihiko.odaki@daynix.com>
  Date:   2023-05-24 (Wed, 24 May 2023)

  Changed paths:
    M util/vfio-helpers.c

  Log Message:
  -----------
  util/vfio-helpers: Use g_file_read_link()

When _FORTIFY_SOURCE=2, glibc version is 2.35, and GCC version is
12.1.0, the compiler complains as follows:

In file included from /usr/include/features.h:490,
                 from /usr/include/bits/libc-header-start.h:33,
                 from /usr/include/stdint.h:26,
                 from 
/usr/lib/gcc/aarch64-unknown-linux-gnu/12.1.0/include/stdint.h:9,
                 from /home/alarm/q/var/qemu/include/qemu/osdep.h:94,
                 from ../util/vfio-helpers.c:13:
In function 'readlink',
    inlined from 'sysfs_find_group_file' at ../util/vfio-helpers.c:116:9,
    inlined from 'qemu_vfio_init_pci' at ../util/vfio-helpers.c:326:18,
    inlined from 'qemu_vfio_open_pci' at ../util/vfio-helpers.c:517:9:
/usr/include/bits/unistd.h:119:10: error: argument 2 is null but the 
corresponding size argument 3 value is 4095 [-Werror=nonnull]
  119 |   return __glibc_fortify (readlink, __len, sizeof (char),
      |          ^~~~~~~~~~~~~~~

This error implies the allocated buffer can be NULL. Use
g_file_read_link(), which allocates buffer automatically to avoid the
error.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>


  Commit: b300c134465465385045ab705b68a42699688332
      
https://github.com/qemu/qemu/commit/b300c134465465385045ab705b68a42699688332
  Author: Richard Henderson <richard.henderson@linaro.org>
  Date:   2023-05-24 (Wed, 24 May 2023)

  Changed paths:
    M hw/vfio/pci.c
    M util/vfio-helpers.c

  Log Message:
  -----------
  Merge tag 'pull-vfio-20230524' of https://github.com/legoater/qemu into 
staging

vfio queue:

* Fix for a memory corruption due to an extra free
* Fix for a compile breakage

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* tag 'pull-vfio-20230524' of https://github.com/legoater/qemu:
  util/vfio-helpers: Use g_file_read_link()
  vfio/pci: Fix a use-after-free issue

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>


Compare: https://github.com/qemu/qemu/compare/8acf865084a1...b300c1344654