PM: hibernate: fix crashes with init_on_free=1
authorAlexander Potapenko <glider@google.com>
Thu, 16 Jan 2020 11:09:34 +0000 (12:09 +0100)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Thu, 16 Jan 2020 22:51:45 +0000 (23:51 +0100)
commit18451f9f9e5810b8bd1245c5ae166f257e0e2b9d
tree1c2fbb83b60b6f165779b8414af59653d434f370
parentb3a987b0264d3ddbb24293ebff10eddfc472f653
PM: hibernate: fix crashes with init_on_free=1

Upon resuming from hibernation, free pages may contain stale data from
the kernel that initiated the resume. This breaks the invariant
inflicted by init_on_free=1 that freed pages must be zeroed.

To deal with this problem, make clear_free_pages() also clear the free
pages when init_on_free is enabled.

Fixes: 6471384af2a6 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options")
Reported-by: Johannes Stezenbach <js@sig21.net>
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: 5.3+ <stable@vger.kernel.org> # 5.3+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
kernel/power/snapshot.c