diff options
| author | Mel Gorman <mgorman@suse.de> | 2014-10-02 19:47:41 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-11-05 20:27:46 +0000 |
| commit | b47191f7d729d2fabd29fbbf3d57158133d4e0ef (patch) | |
| tree | 765c1f3940f4dbf8e5630ed5310e078bb615dd2b /kernel/events | |
| parent | 6bf3b2e3ac32809477278d73c9e7a57d7ba82090 (diff) | |
| download | kernel_samsung_smdk4412-b47191f7d729d2fabd29fbbf3d57158133d4e0ef.zip kernel_samsung_smdk4412-b47191f7d729d2fabd29fbbf3d57158133d4e0ef.tar.gz kernel_samsung_smdk4412-b47191f7d729d2fabd29fbbf3d57158133d4e0ef.tar.bz2 | |
mm: migrate: Close race between migration completion and mprotect
commit d3cb8bf6081b8b7a2dabb1264fe968fd870fa595 upstream.
A migration entry is marked as write if pte_write was true at the time the
entry was created. The VMA protections are not double checked when migration
entries are being removed as mprotect marks write-migration-entries as
read. It means that potentially we take a spurious fault to mark PTEs write
again but it's straight-forward. However, there is a race between write
migrations being marked read and migrations finishing. This potentially
allows a PTE to be write that should have been read. Close this race by
double checking the VMA permissions using maybe_mkwrite when migration
completes.
[torvalds@linux-foundation.org: use maybe_mkwrite]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'kernel/events')
0 files changed, 0 insertions, 0 deletions