From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 69D9E1D68D for ; Wed, 4 Oct 2023 18:24:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="B1ZoR7Kl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DF577C433C9; Wed, 4 Oct 2023 18:24:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1696443891; bh=Ya/C+ivrtOVhKh3vMf5raxjiG4WvYa/2+zIlCOd6CLw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=B1ZoR7KlwBgcukixORU8+Iunl9jO5SSMB+CxDzKSvX8jLCDRubAVpSsj2XbwspUeK rumPOJ3ph2priFHo134loKhjMC0yzvFYEF6ORnNT/lNI4hz34Qj20A3JWcBbCiSPV+ yVqWTS8DF+e+DYDB4S6KGNTlhAlkmkWa1g/dpsP4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+291100dcb32190ec02a8@syzkaller.appspotmail.com, Eduard Zingerman , Martin KaFai Lau , Sasha Levin Subject: [PATCH 6.5 028/321] bpf: Avoid dummy bpf_offload_netdev in __bpf_prog_dev_bound_init Date: Wed, 4 Oct 2023 19:52:53 +0200 Message-ID: <20231004175230.473588679@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231004175229.211487444@linuxfoundation.org> References: <20231004175229.211487444@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eduard Zingerman [ Upstream commit 1a49f4195d3498fe458a7f5ff7ec5385da70d92e ] Fix for a bug observable under the following sequence of events: 1. Create a network device that does not support XDP offload. 2. Load a device bound XDP program with BPF_F_XDP_DEV_BOUND_ONLY flag (such programs are not offloaded). 3. Load a device bound XDP program with zero flags (such programs are offloaded). At step (2) __bpf_prog_dev_bound_init() associates with device (1) a dummy bpf_offload_netdev struct with .offdev field set to NULL. At step (3) __bpf_prog_dev_bound_init() would reuse dummy struct allocated at step (2). However, downstream usage of the bpf_offload_netdev assumes that .offdev field can't be NULL, e.g. in bpf_prog_offload_verifier_prep(). Adjust __bpf_prog_dev_bound_init() to require bpf_offload_netdev with non-NULL .offdev for offloaded BPF programs. Fixes: 2b3486bc2d23 ("bpf: Introduce device-bound XDP programs") Reported-by: syzbot+291100dcb32190ec02a8@syzkaller.appspotmail.com Closes: https://lore.kernel.org/bpf/000000000000d97f3c060479c4f8@google.com/ Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20230912005539.2248244-2-eddyz87@gmail.com Signed-off-by: Martin KaFai Lau Signed-off-by: Sasha Levin --- kernel/bpf/offload.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c index 8a26cd8814c1b..e842229123ffc 100644 --- a/kernel/bpf/offload.c +++ b/kernel/bpf/offload.c @@ -198,12 +198,14 @@ static int __bpf_prog_dev_bound_init(struct bpf_prog *prog, struct net_device *n offload->netdev = netdev; ondev = bpf_offload_find_netdev(offload->netdev); + /* When program is offloaded require presence of "true" + * bpf_offload_netdev, avoid the one created for !ondev case below. + */ + if (bpf_prog_is_offloaded(prog->aux) && (!ondev || !ondev->offdev)) { + err = -EINVAL; + goto err_free; + } if (!ondev) { - if (bpf_prog_is_offloaded(prog->aux)) { - err = -EINVAL; - goto err_free; - } - /* When only binding to the device, explicitly * create an entry in the hashtable. */ -- 2.40.1