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 53DE71863 for ; Wed, 28 Dec 2022 15:50:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C7F91C433D2; Wed, 28 Dec 2022 15:49:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672242600; bh=t8zlbSGSsooAWtq4TLVBiXeczbyuDynXBmG8sjChtnU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bN6mftvuglVE4qsA/1lXMzZinY6Q3/SB484eFxBmBJONXYYdV/evphGWMuzb9LlCW TooO7MAvmx21CqQ2Qw8zHkn4j/LxiXhp+lYkQtEcMtpvw2gWHrswvg5DoNWWippWs0 BaaMq0wApyFkZXz2psLsud8hj82EV28THaJ6NBlw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Pengcheng Yang , Daniel Borkmann , Jakub Sitnicki , Sasha Levin Subject: [PATCH 6.0 0430/1073] bpf, sockmap: Fix repeated calls to sock_put() when msg has more_data Date: Wed, 28 Dec 2022 15:33:38 +0100 Message-Id: <20221228144339.707234303@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144328.162723588@linuxfoundation.org> References: <20221228144328.162723588@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Pengcheng Yang [ Upstream commit 7a9841ca025275b5b0edfb0b618934abb6ceec15 ] In tcp_bpf_send_verdict() redirection, the eval variable is assigned to __SK_REDIRECT after the apply_bytes data is sent, if msg has more_data, sock_put() will be called multiple times. We should reset the eval variable to __SK_NONE every time more_data starts. This causes: IPv4: Attempt to release TCP socket in state 1 00000000b4c925d7 ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 5 PID: 4482 at lib/refcount.c:25 refcount_warn_saturate+0x7d/0x110 Modules linked in: CPU: 5 PID: 4482 Comm: sockhash_bypass Kdump: loaded Not tainted 6.0.0 #1 Hardware name: Red Hat KVM, BIOS 1.11.0-2.el7 04/01/2014 Call Trace: __tcp_transmit_skb+0xa1b/0xb90 ? __alloc_skb+0x8c/0x1a0 ? __kmalloc_node_track_caller+0x184/0x320 tcp_write_xmit+0x22a/0x1110 __tcp_push_pending_frames+0x32/0xf0 do_tcp_sendpages+0x62d/0x640 tcp_bpf_push+0xae/0x2c0 tcp_bpf_sendmsg_redir+0x260/0x410 ? preempt_count_add+0x70/0xa0 tcp_bpf_send_verdict+0x386/0x4b0 tcp_bpf_sendmsg+0x21b/0x3b0 sock_sendmsg+0x58/0x70 __sys_sendto+0xfa/0x170 ? xfd_validate_state+0x1d/0x80 ? switch_fpu_return+0x59/0xe0 __x64_sys_sendto+0x24/0x30 do_syscall_64+0x37/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: cd9733f5d75c ("tcp_bpf: Fix one concurrency problem in the tcp_bpf_send_verdict function") Signed-off-by: Pengcheng Yang Signed-off-by: Daniel Borkmann Acked-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/1669718441-2654-2-git-send-email-yangpc@wangsu.com Signed-off-by: Sasha Levin --- net/ipv4/tcp_bpf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index cf9c3e8f7ccb..f3e868f4cd9e 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -279,7 +279,7 @@ static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock, bool cork = false, enospc = sk_msg_full(msg); struct sock *sk_redir; u32 tosend, origsize, sent, delta = 0; - u32 eval = __SK_NONE; + u32 eval; int ret; more_data: @@ -310,6 +310,7 @@ static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock, tosend = msg->sg.size; if (psock->apply_bytes && psock->apply_bytes < tosend) tosend = psock->apply_bytes; + eval = __SK_NONE; switch (psock->eval) { case __SK_PASS: -- 2.35.1