linux-kernel - [PATCH 4.14 094/100] s390/mm: Check for valid vma before zapping in gmap

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20181129140106.874898228@linuxfoundation.org>
Date:   Thu, 29 Nov 2018 15:13:04 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Janosch Frank <frankja@...ux.ibm.com>,
        David Hildenbrand <david@...hat.com>,
        Dan Carpenter <dan.carpenter@...cle.com>
Subject: [PATCH 4.14 094/100] s390/mm: Check for valid vma before zapping in gmap_discard

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Janosch Frank <frankja@...ux.ibm.com>

commit 1843abd03250115af6cec0892683e70cf2297c25 upstream.

Userspace could have munmapped the area before doing unmapping from
the gmap. This would leave us with a valid vmaddr, but an invalid vma
from which we would try to zap memory.

Let's check before using the vma.

Fixes: 1e133ab296f3 ("s390/mm: split arch/s390/mm/pgtable.c")
Signed-off-by: Janosch Frank <frankja@...ux.ibm.com>
Reviewed-by: David Hildenbrand <david@...hat.com>
Reported-by: Dan Carpenter <dan.carpenter@...cle.com>
Message-Id: <20180816082432.78828-1-frankja@...ux.ibm.com>
Signed-off-by: Janosch Frank <frankja@...ux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>


---
 arch/s390/mm/gmap.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -689,6 +689,8 @@ void gmap_discard(struct gmap *gmap, uns
 		vmaddr |= gaddr & ~PMD_MASK;
 		/* Find vma in the parent mm */
 		vma = find_vma(gmap->mm, vmaddr);
+		if (!vma)
+			continue;
 		size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK));
 		zap_page_range(vma, vmaddr, size);
 	}