linux-kernel - Re: [PATCH] Bug in fs/afs/write.c function afs_write_back_from_locked

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: <10764.1178800398@redhat.com>
Date:	Thu, 10 May 2007 13:33:18 +0100
From:	David Howells <dhowells@...hat.com>
To:	mikukkon@....fi
Cc:	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] Bug in fs/afs/write.c function afs_write_back_from_locked_page()


How about the attached instead?

David
---
AFS: Fix interminable loop in afs_write_back_from_locked_page()

From: Mika Kukkonen <mikukkon@...u.homelinux.net>

Following bug was uncovered by compiling with '-W' flag:

  CC [M]  fs/afs/write.o
fs/afs/write.c: In function ‘afs_write_back_from_locked_page’:
fs/afs/write.c:398: warning: comparison of unsigned expression >= 0 is always true

Loop variable 'n' is unsigned, so wraps around happily as far as I can
see. Trival fix attached (compile tested only).

Signed-Off-By: Mika Kukkonen <mikukkon@....fi>
Signed-off-by: David Howells <dhowells@...hat.com>
---

 fs/afs/write.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/afs/write.c b/fs/afs/write.c
index 67ae4db..c26d5e8 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -395,8 +395,10 @@ static int afs_write_back_from_locked_page(struct afs_writeback *wb,
 		if (n == 0)
 			goto no_more;
 		if (pages[0]->index != start) {
-			for (n--; n >= 0; n--)
-				put_page(pages[n]);
+			do {
+				put_page(pages[--n]);
+			} while (n > 0);
+			put_page(pages[0]);
 			goto no_more;
 		}
 
-
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/