From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760376Ab2CNJyw (ORCPT ); Wed, 14 Mar 2012 05:54:52 -0400 Received: from ozlabs.org ([203.10.76.45]:34679 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759079Ab2CNJys (ORCPT ); Wed, 14 Mar 2012 05:54:48 -0400 Date: Wed, 14 Mar 2012 20:54:27 +1100 From: Anton Blanchard To: dhowells@redhat.com Cc: linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org Subject: [PATCH] afs: Remote abort can cause BUG in rxrpc code Message-ID: <20120314205427.71a11c97@kryten> X-Mailer: Claws Mail 3.7.8 (GTK+ 2.24.4; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When writing files to afs I sometimes hit a BUG: kernel BUG at fs/afs/rxrpc.c:179! With a backtrace of: afs_free_call afs_make_call afs_fs_store_data afs_vnode_store_data afs_write_back_from_locked_page afs_writepages_region afs_writepages The cause is: ASSERT(skb_queue_empty(&call->rx_queue)); Looking at a tcpdump of the session the abort happens because we are exceeding our disk quota: rx abort fs reply store-data error diskquota exceeded (32) So the abort error is valid. We hit the BUG because we haven't freed all the resources for the call. By freeing any skbs in call->rx_queue before calling afs_free_call we avoid hitting leaking memory and avoid hitting the BUG. Signed-off-by: Anton Blanchard Cc: --- Index: linux-build/fs/afs/rxrpc.c =================================================================== --- linux-build.orig/fs/afs/rxrpc.c 2012-03-14 20:29:22.990351454 +1100 +++ linux-build/fs/afs/rxrpc.c 2012-03-14 20:30:51.039953546 +1100 @@ -314,6 +314,7 @@ int afs_make_call(struct in_addr *addr, struct msghdr msg; struct kvec iov[1]; int ret; + struct sk_buff *skb; _enter("%x,{%d},", addr->s_addr, ntohs(call->port)); @@ -380,6 +381,8 @@ int afs_make_call(struct in_addr *addr, error_do_abort: rxrpc_kernel_abort_call(rxcall, RX_USER_ABORT); + while ((skb = skb_dequeue(&call->rx_queue))) + afs_free_skb(skb); rxrpc_kernel_end_call(rxcall); call->rxcall = NULL; error_kill_call: