ipc, shm: guard against non-existant vma in shmdt(2)
authorDavidlohr Bueso <davidlohr.bueso@hp.com>
Wed, 11 Sep 2013 21:26:28 +0000 (14:26 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 18 Oct 2013 17:55:01 +0000 (10:55 -0700)
commit38635ab21b23cc474c6017667a7736f5b55d3bfb
tree74a96847e9fdf978fd0fcb531d04e3103263d747
parente6290aa76894ece28cdb86d1c4f21fe25763d3a0
ipc, shm: guard against non-existant vma in shmdt(2)

commit 530fcd16d87cd2417c472a581ba5a1e501556c86 upstream.

When !CONFIG_MMU there's a chance we can derefence a NULL pointer when the
VM area isn't found - check the return value of find_vma().

Also, remove the redundant -EINVAL return: retval is set to the proper
return code and *only* changed to 0, when we actually unmap the segments.

Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipc/shm.c