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From: Davidlohr Bueso <dave@stgolabs.net>
To: akpm@linux-foundation.org, aarcange@redhat.com
Cc: joe.lawrence@redhat.com, gareth.evans@contextis.co.uk,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	dave@stgolabs.net, stable@kernel.org
Subject: [PATCH -next 0/2] ipc/shm: shmat() fixes around nil-page
Date: Thu,  3 May 2018 13:32:41 -0700	[thread overview]
Message-ID: <20180503203243.15045-1-dave@stgolabs.net> (raw)

Hi,

These patches fix two issues reported[1] a while back by Joe and Andrea
around how shmat(2) behaves with nil-page.

The first reverts a commit that it was incorrectly thought that mapping
nil-page (address=0) was a no no with MAP_FIXED. This is not the case,
with the exception of SHM_REMAP; which is address in the second patch.

I chose two patches because it is easier to backport and it explicitly
reverts bogus behaviour. Both patches ought to be in -stable and ltp
testcases need updated (the added testcase around the cve can be modified
to just test for SHM_RND|SHM_REMAP).

[1] lkml.kernel.org/r/20180430172152.nfa564pvgpk3ut7p@linux-n805

Thanks! 

Davidlohr Bueso (2):
  Revert "ipc/shm: Fix shmat mmap nil-page protection"
  ipc/shm: fix shmat() nil address after round-down when remapping

 ipc/shm.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

-- 
2.13.6

             reply	other threads:[~2018-05-03 20:47 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-03 20:32 Davidlohr Bueso [this message]
2018-05-03 20:32 ` [PATCH 1/2] Revert "ipc/shm: Fix shmat mmap nil-page protection" Davidlohr Bueso
2018-05-03 20:49 ` [PATCH 2/2] ipc/shm: fix shmat() nil address after round-down when remapping Davidlohr Bueso
2018-05-10 18:17 ` [PATCH -next 0/2] ipc/shm: shmat() fixes around nil-page Vlastimil Babka
2018-05-14 16:19   ` Davidlohr Bueso

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