From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BAE18C43381 for ; Mon, 25 Feb 2019 21:35:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D66121841 for ; Mon, 25 Feb 2019 21:35:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551130500; bh=wBPMrdg7x4K4mkimPpACCGXdQrBZg+dirlRsJEwAg/Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=lG3b+GVZxBrGW+u9PfVOp3wSXbddRoKSYR7lS0QGoFaUXiDT3VrvB9CL+Ec5fkfd9 sdGUgSqvY+hZ6olYSI/JRyip35NDNq0UdQxtGThj7Rh4qTvIzGuUZyrtsGcw92BoyQ evLHklPFvnzfbfKKk+2naF4LPjl67Q8JUpXcdRJs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732901AbfBYVe7 (ORCPT ); Mon, 25 Feb 2019 16:34:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:41086 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732889AbfBYVe4 (ORCPT ); Mon, 25 Feb 2019 16:34:56 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F1BA421850; Mon, 25 Feb 2019 21:34:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551130495; bh=wBPMrdg7x4K4mkimPpACCGXdQrBZg+dirlRsJEwAg/Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0fCld01viIv7PhD1vPoM7rgOBepuquDQWpUSepjymIQM05l/Ob6cdTEVvbbc0c/+b T5yTZrgkXzF0tzqBZ874KtVbjJRC0lMYUl0cUInAam3skMp3cSAWKLvMzHG1BgiIQQ Ne3anuYSVG/D5n/vxCAVSq76hWpn+/U7+P54nEaM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marc Dionne , David Howells , Sasha Levin Subject: [PATCH 4.20 102/183] afs: Dont set vnode->cb_s_break in afs_validate() Date: Mon, 25 Feb 2019 22:11:15 +0100 Message-Id: <20190225195111.885639018@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190225195054.748060397@linuxfoundation.org> References: <20190225195054.748060397@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 4882a27cec24319d10f95e978ecc80050e3e3e15 ] A cb_interest record is not necessarily attached to the vnode on entry to afs_validate(), which can cause an oops when we try to bring the vnode's cb_s_break up to date in the default case (ie. no current callback promise and the vnode has not been deleted). Fix this by simply removing the line, as vnode->cb_s_break will be set when needed by afs_register_server_cb_interest() when we next get a callback promise from RPC call. The oops looks something like: BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 ... RIP: 0010:afs_validate+0x66/0x250 [kafs] ... Call Trace: afs_d_revalidate+0x8d/0x340 [kafs] ? __d_lookup+0x61/0x150 lookup_dcache+0x44/0x70 ? lookup_dcache+0x44/0x70 __lookup_hash+0x24/0xa0 do_unlinkat+0x11d/0x2c0 __x64_sys_unlink+0x23/0x30 do_syscall_64+0x4d/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: ae3b7361dc0e ("afs: Fix validation/callback interaction") Signed-off-by: Marc Dionne Signed-off-by: David Howells Signed-off-by: Sasha Levin --- fs/afs/inode.c | 1 - 1 file changed, 1 deletion(-) diff --git a/fs/afs/inode.c b/fs/afs/inode.c index 6b17d36204142..211343831c304 100644 --- a/fs/afs/inode.c +++ b/fs/afs/inode.c @@ -414,7 +414,6 @@ int afs_validate(struct afs_vnode *vnode, struct key *key) } else if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { valid = true; } else { - vnode->cb_s_break = vnode->cb_interest->server->cb_s_break; vnode->cb_v_break = vnode->volume->cb_v_break; valid = false; } -- 2.19.1