Received-SPF: pass (google.com: domain of linux-kernel+bounces-8565-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley
	Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United
	Kingdom.
	Registered in England and Wales under Company Registration No. 3798903
From: David Howells <dhowells@redhat.com>
To: Anastasia Belova <abelova@astralinux.ru>,
    Marc Dionne <marc.dionne@auristor.com>
cc: dhowells@redhat.com, linux-afs@lists.infradead.org,
    linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
    lvc-project@linuxtesting.org
Subject: [PATCH] afs: Fix overwriting of result of DNS query
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <1700861.1703168632.1@warthog.procyon.org.uk>
Content-Transfer-Encoding: quoted-printable
Date: Thu, 21 Dec 2023 14:23:52 +0000
Message-ID: <1700862.1703168632@warthog.procyon.org.uk>

In afs_update_cell(), ret is the result of the DNS lookup and the errors
are to be handled by a switch - however, the value gets clobbered in
between by setting it to -ENOMEM in case afs_alloc_vlserver_list() fails.

Fix this by moving the setting of -ENOMEM into the error handling for OOM
failure.  Further, only do it if we don't have an alternative error to
return.

Found by Linux Verification Center (linuxtesting.org) with SVACE.  Based o=
n
a patch from Anastasia Belova[1].

Fixes: d5c32c89b208 ("afs: Fix cell DNS lookup")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Anastasia Belova <abelova@astralinux.ru>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: lvc-project@linuxtesting.org
Link: https://lore.kernel.org/r/20231221085849.1463-1-abelova@astralinux.r=
u/ [1]

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

diff --git a/fs/afs/cell.c b/fs/afs/cell.c
index 988c2ac7cece..926cb1188eba 100644
--- a/fs/afs/cell.c
+++ b/fs/afs/cell.c
@@ -409,10 +409,12 @@ static int afs_update_cell(struct afs_cell *cell)
 		if (ret =3D=3D -ENOMEM)
 			goto out_wake;
 =

-		ret =3D -ENOMEM;
 		vllist =3D afs_alloc_vlserver_list(0);
-		if (!vllist)
+		if (!vllist) {
+			if (ret >=3D 0)
+				ret =3D -ENOMEM;
 			goto out_wake;
+		}
 =

 		switch (ret) {
 		case -ENODATA: