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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 1D994C282CA for ; Wed, 13 Feb 2019 02:59:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D20602190A for ; Wed, 13 Feb 2019 02:59:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550026790; bh=7H1SuANf+FOD1J1TmCN2mSpoS0LLIz9UPWYuuGlOidk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=a6yQjJsoM13BA5K1yyCD+6qYD3oQR5+WZSBbMo4cRcmMLv2omi7gwcekUdKDXamri c8M0WPvjwGFr6pvks5w1ZCq7v77etBgg/RIQ6/AzH02NN4HTPmp814dBqbN0U3sSjE sTHMudsdKa3dVm8mQ7oGvejMj0o7r9sjAP97ki+U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390232AbfBMC7s (ORCPT ); Tue, 12 Feb 2019 21:59:48 -0500 Received: from mail.kernel.org ([198.145.29.99]:39858 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731764AbfBMCgP (ORCPT ); Tue, 12 Feb 2019 21:36:15 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5CD4C222CD; Wed, 13 Feb 2019 02:36:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550025375; bh=7H1SuANf+FOD1J1TmCN2mSpoS0LLIz9UPWYuuGlOidk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XkeJG2ahV/bfDG5sUGMEN4hgR2SYltfkagH5WUIkmmNWfcw7cRzUFgriOaeAKJwM3 ftcNc53mn8ISKCiKxpjoTLsRUij/GXZjzLiUced/7lUhTsRc++dUfpAiZx4t5mWq9p /a6pVvfJCjx3f49kQf5yd1fswbeVMVGm/wVPlm98= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Marc Dionne , David Howells , Sasha Levin , linux-afs@lists.infradead.org Subject: [PATCH AUTOSEL 4.20 085/105] afs: Don't set vnode->cb_s_break in afs_validate() Date: Tue, 12 Feb 2019 21:33:16 -0500 Message-Id: <20190213023336.19019-85-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190213023336.19019-1-sashal@kernel.org> References: <20190213023336.19019-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marc Dionne [ 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 6b17d3620414..211343831c30 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