From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [91.216.245.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2E6761AF0AB for ; Mon, 4 Nov 2024 09:44:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.216.245.30 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730713482; cv=none; b=Atwh+mSe+P34yV1czLrG2zfras56M9Z9urjeBb87AOtS/OxQ9kFlPH6wYz1TgJ1dbmpDXEzfTbIlAZdydRxNIIFgXjsvzFAEn0moGvTopdWU/1v+ua+BSDm8sWk0ffYhgb+6InOra6D/f5uWXHZJx190x8j/CCTtqd1RAUC9gNQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730713482; c=relaxed/simple; bh=OYW2rbxVqkRXC9f7wIfH7w3sTZqlkxAVl8uyDydlt9o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=u8CtEdODq4h7/y/sy6Q+p+5cIPFeTqp5KDifz22drjNpifK6OhQke5KKNPivQ8b5uZNiEw5TFp4lr9WHAsOgsygdgnoKzCXQYIHUdQrQjyGl9rXM3eN6K5g7kPgMTOp/IgV2RDOTentxmdmueg1jaR53ZsdZwFN3zzrWYCvD0AU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de; spf=pass smtp.mailfrom=breakpoint.cc; arc=none smtp.client-ip=91.216.245.30 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strlen.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=breakpoint.cc Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1t7tdW-0003dR-M8; Mon, 04 Nov 2024 10:44:38 +0100 From: Florian Westphal To: Cc: Florian Westphal Subject: [PATCH nf-next v3 7/7] netfilter: nf_tables: must hold rcu read lock while iterating object type list Date: Mon, 4 Nov 2024 10:41:19 +0100 Message-ID: <20241104094126.16917-8-fw@strlen.de> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20241104094126.16917-1-fw@strlen.de> References: <20241104094126.16917-1-fw@strlen.de> Precedence: bulk X-Mailing-List: netfilter-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Update of stateful object triggers: WARNING: suspicious RCU usage net/netfilter/nf_tables_api.c:7759 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by nft/3060: #0: ffff88810f0578c8 (&nft_net->commit_mutex){+.+.}-{4:4}, [..] ... but this list is not protected by the transaction mutex but the nfnl nftables subsystem mutex. Switch to nft_obj_type_get which will acquire rcu read lock, bump refcount, and returns the result. v3: Dan Carpenter points out nft_obj_type_get returns error pointer, not NULL, on error. Fixes: dad3bdeef45f ("netfilter: nf_tables: fix memory leak during stateful obj update"). Signed-off-by: Florian Westphal --- net/netfilter/nf_tables_api.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index de8e48a5c62d..b7a817e483aa 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -7809,9 +7809,7 @@ static int nf_tables_updobj(const struct nft_ctx *ctx, struct nft_trans *trans; int err = -ENOMEM; - if (!try_module_get(type->owner)) - return -ENOENT; - + /* caller must have obtained type->owner reference. */ trans = nft_trans_alloc(ctx, NFT_MSG_NEWOBJ, sizeof(struct nft_trans_obj)); if (!trans) @@ -7879,15 +7877,16 @@ static int nf_tables_newobj(struct sk_buff *skb, const struct nfnl_info *info, if (info->nlh->nlmsg_flags & NLM_F_REPLACE) return -EOPNOTSUPP; - type = __nft_obj_type_get(objtype, family); - if (WARN_ON_ONCE(!type)) - return -ENOENT; - if (!obj->ops->update) return 0; + type = nft_obj_type_get(net, objtype, family); + if (WARN_ON_ONCE(IS_ERR(type))) + return PTR_ERR(type); + nft_ctx_init(&ctx, net, skb, info->nlh, family, table, NULL, nla); + /* type->owner reference is put when transaction object is released. */ return nf_tables_updobj(&ctx, type, nla[NFTA_OBJ_DATA], obj); } -- 2.45.2