linux-kernel - [PATCH 06/12] fscache: Detect multiple relinquishment of a cookie

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]

Date:   Wed, 04 Apr 2018 23:07:24 +0100
From:   David Howells <dhowells@...hat.com>
To:     torvalds@...ux-foundation.org
Cc:     linux-nfs@...r.kernel.org, linux-kernel@...r.kernel.org,
        dhowells@...hat.com, linux-cachefs@...hat.com,
        linux-fsdevel@...r.kernel.org, linux-afs@...ts.infradead.org
Subject: [PATCH 06/12] fscache: Detect multiple relinquishment of a cookie

Report if an fscache cookie is relinquished multiple times by the netfs.

Signed-off-by: David <dhowells@...hat.com>
---

 fs/fscache/cookie.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index d705125665f0..98d22f495cd8 100644
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -602,7 +602,8 @@ void __fscache_relinquish_cookie(struct fscache_cookie *cookie, bool retire)
 	       atomic_read(&cookie->n_active), retire);
 
 	/* No further netfs-accessing operations on this cookie permitted */
-	set_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags);
+	if (test_and_set_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags))
+		BUG();
 
 	__fscache_disable_cookie(cookie, retire);