linux-kernel - [104/107] vm: fix vm_pgoff wrap in upward expansion

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: <20111102221459.650206488@clark.kroah.org>
Date:	Wed, 02 Nov 2011 15:15:10 -0700
From:	Greg KH <gregkh@...e.de>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	torvalds@...ux-foundation.org, akpm@...ux-foundation.org,
	alan@...rguk.ukuu.org.uk, Hugh Dickins <hughd@...gle.com>
Subject: [104/107] vm: fix vm_pgoff wrap in upward expansion

2.6.32-longterm review patch.  If anyone has any objections, please let us know.

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

From: Hugh Dickins <hughd@...gle.com>

commit 42c36f63ac1366ab0ecc2d5717821362c259f517 upstream.

Commit a626ca6a6564 ("vm: fix vm_pgoff wrap in stack expansion") fixed
the case of an expanding mapping causing vm_pgoff wrapping when you had
downward stack expansion.  But there was another case where IA64 and
PA-RISC expand mappings: upward expansion.

This fixes that case too.

Signed-off-by: Hugh Dickins <hughd@...gle.com>
Signed-off-by: Linus Torvalds <torvalds@...ux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>

---
 mm/mmap.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1636,9 +1636,12 @@ int expand_upwards(struct vm_area_struct
 		size = address - vma->vm_start;
 		grow = (address - vma->vm_end) >> PAGE_SHIFT;
 
-		error = acct_stack_growth(vma, size, grow);
-		if (!error)
-			vma->vm_end = address;
+		error = -ENOMEM;
+		if (vma->vm_pgoff + (size >> PAGE_SHIFT) >= vma->vm_pgoff) {
+			error = acct_stack_growth(vma, size, grow);
+			if (!error)
+				vma->vm_end = address;
+		}
 	}
 	anon_vma_unlock(vma);
 	return error;


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/