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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C4D60C7EE22 for ; Mon, 8 May 2023 10:08:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234105AbjEHKIT (ORCPT ); Mon, 8 May 2023 06:08:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36680 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234100AbjEHKIS (ORCPT ); Mon, 8 May 2023 06:08:18 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7BFCB32926 for ; Mon, 8 May 2023 03:08:16 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 05B9A6236E for ; Mon, 8 May 2023 10:08:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1A7E4C433EF; Mon, 8 May 2023 10:08:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683540495; bh=hDe++XOS1xnfE2Ty7geFW3kAx3JIFleArPvdkBMyqfo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QrtQglyzID+gbYE3GWVVKX6uknL2TnvgK8zmDTBsdLQZ9q2tar5qCJp19hV3XmE8J uhzjsB94cwfnYZ8wCMrfcmR3ABfQAuRioq5vDkc0HIRLHtnmuvSLNAEeGpDP1TCEHc ueB3bZTdncAosZokGfefrKQHpuDSWRYsRuQyAeFQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+49f6cef45247ff249498@syzkaller.appspotmail.com, Hsin-Wei Hung , Xin Liu , John Fastabend , Daniel Borkmann , Sasha Levin Subject: [PATCH 6.1 345/611] bpf, sockmap: Revert buggy deadlock fix in the sockhash and sockmap Date: Mon, 8 May 2023 11:43:07 +0200 Message-Id: <20230508094433.626365535@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508094421.513073170@linuxfoundation.org> References: <20230508094421.513073170@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Daniel Borkmann [ Upstream commit 8c5c2a4898e3d6bad86e29d471e023c8a19ba799 ] syzbot reported a splat and bisected it to recent commit ed17aa92dc56 ("bpf, sockmap: fix deadlocks in the sockhash and sockmap"): [...] WARNING: CPU: 1 PID: 9280 at kernel/softirq.c:376 __local_bh_enable_ip+0xbe/0x130 kernel/softirq.c:376 Modules linked in: CPU: 1 PID: 9280 Comm: syz-executor.1 Not tainted 6.2.0-syzkaller-13249-gd319f344561d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 RIP: 0010:__local_bh_enable_ip+0xbe/0x130 kernel/softirq.c:376 [...] Call Trace: spin_unlock_bh include/linux/spinlock.h:395 [inline] sock_map_del_link+0x2ea/0x510 net/core/sock_map.c:165 sock_map_unref+0xb0/0x1d0 net/core/sock_map.c:184 sock_hash_delete_elem+0x1ec/0x2a0 net/core/sock_map.c:945 map_delete_elem kernel/bpf/syscall.c:1536 [inline] __sys_bpf+0x2edc/0x53e0 kernel/bpf/syscall.c:5053 __do_sys_bpf kernel/bpf/syscall.c:5166 [inline] __se_sys_bpf kernel/bpf/syscall.c:5164 [inline] __x64_sys_bpf+0x79/0xc0 kernel/bpf/syscall.c:5164 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fe8f7c8c169 [...] Revert for now until we have a proper solution. Fixes: ed17aa92dc56 ("bpf, sockmap: fix deadlocks in the sockhash and sockmap") Reported-by: syzbot+49f6cef45247ff249498@syzkaller.appspotmail.com Cc: Hsin-Wei Hung Cc: Xin Liu Cc: John Fastabend Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/000000000000f1db9605f939720e@google.com/ Signed-off-by: Sasha Levin --- net/core/sock_map.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 2408965e5c7b6..a68a7290a3b2b 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -414,9 +414,8 @@ static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test, { struct sock *sk; int err = 0; - unsigned long flags; - raw_spin_lock_irqsave(&stab->lock, flags); + raw_spin_lock_bh(&stab->lock); sk = *psk; if (!sk_test || sk_test == sk) sk = xchg(psk, NULL); @@ -426,7 +425,7 @@ static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test, else err = -EINVAL; - raw_spin_unlock_irqrestore(&stab->lock, flags); + raw_spin_unlock_bh(&stab->lock); return err; } @@ -924,12 +923,11 @@ static int sock_hash_delete_elem(struct bpf_map *map, void *key) struct bpf_shtab_bucket *bucket; struct bpf_shtab_elem *elem; int ret = -ENOENT; - unsigned long flags; hash = sock_hash_bucket_hash(key, key_size); bucket = sock_hash_select_bucket(htab, hash); - raw_spin_lock_irqsave(&bucket->lock, flags); + raw_spin_lock_bh(&bucket->lock); elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size); if (elem) { hlist_del_rcu(&elem->node); @@ -937,7 +935,7 @@ static int sock_hash_delete_elem(struct bpf_map *map, void *key) sock_hash_free_elem(htab, elem); ret = 0; } - raw_spin_unlock_irqrestore(&bucket->lock, flags); + raw_spin_unlock_bh(&bucket->lock); return ret; } -- 2.39.2