ARM: missing ->mmap_sem around find_vma() in swp_emulate.c
authorAl Viro <viro@ZenIV.linux.org.uk>
Sun, 16 Dec 2012 00:25:57 +0000 (00:25 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 11 Jan 2013 17:07:16 +0000 (09:07 -0800)
commitebd3b1a320baa264c7662363fa4b930634470a4b
tree37b48c62993286f17718003f721625c7c42e6894
parent99574fa03e407cad20953d7cbfcb0056f02e811e
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>
arch/arm/kernel/swp_emulate.c