tree 60d18dd22003e80798fdc9be7a4edd2b59b9231c
parent a928c9336221b5269cfd168e4f6b5dbe709cc564
author Al Viro <viro@ZenIV.linux.org.uk> 1355617557 +0000
committer chrmhoffmann <chrmhoffmann@gmail.com> 1586074632 +0200

ARM: missing ->mmap_sem around find_vma() in swp_emulate.c

commit 7bf9b7bef881aac820bf1f2e9951a17b09bd7e04 upstream.

find_vma() is *not* safe when somebody else is removing vmas.  Not just
the return value might get bogus just as you are getting it (this instance
doesn't try to dereference the resulting vma), the search itself can get
buggered in rather spectacular ways.  IOW, ->mmap_sem really, really is
not optional here.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>