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 917B1161; Thu, 13 Jun 2024 12:32:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718281956; cv=none; b=Bz/yWZI0OfInmayq6i764N6v0DNqTElffqDVpL3kNJGZ+GrOtsQW1vr+XVYgzp1IdcUXYkmNUDJ5TKO++pokfbqJb4CxW76qVMaMmsTAQz/VKy/gttFskYiS2itgs/1ipkR/HdAIPNWmD3bp6t+EChvPLRkkqQwt4EiDw37ucsE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718281956; c=relaxed/simple; bh=CpEvGxy9PzxSNm+6EX0gl9tiTPuKJxotpgVEyDAHo0w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cY3TckDI0t2KmI5nTq0A38ufxCeydgl7tnG8u8/n39a9+Y3uIAHnof3OgEJ37T9YrGpl+orbvAERmmkh3V8g0VLk079PGFUfpBook2P8wHaYNG+oknKWV7pJa3dg/376z94GBD/qT4W7el+ejADJE/QuDz+VpNGJLYIGQxtFj/s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mNy27121; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="mNy27121" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 18177C2BBFC; Thu, 13 Jun 2024 12:32:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718281956; bh=CpEvGxy9PzxSNm+6EX0gl9tiTPuKJxotpgVEyDAHo0w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mNy27121o0rrF4rbVqsTNXJL8S/Ye4DjS780oRK8ZA2Oq1ZQADEF8rmiqF7xjd/zO FmD9V4uL33GVSozdHi6DyvQa0r5WTf71Az18XDlXf27KG1gaNtZpA/ClkTOBhlOLb2 6A6Mce+okL69tjM4HfXq0TuVTYUfaPXmaEuKBeZQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Breno Leitao , Kuniyuki Iwashima , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 112/402] af_unix: Fix data races in unix_release_sock/unix_stream_sendmsg Date: Thu, 13 Jun 2024 13:31:09 +0200 Message-ID: <20240613113306.499059935@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240613113302.116811394@linuxfoundation.org> References: <20240613113302.116811394@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Breno Leitao [ Upstream commit 540bf24fba16b88c1b3b9353927204b4f1074e25 ] A data-race condition has been identified in af_unix. In one data path, the write function unix_release_sock() atomically writes to sk->sk_shutdown using WRITE_ONCE. However, on the reader side, unix_stream_sendmsg() does not read it atomically. Consequently, this issue is causing the following KCSAN splat to occur: BUG: KCSAN: data-race in unix_release_sock / unix_stream_sendmsg write (marked) to 0xffff88867256ddbb of 1 bytes by task 7270 on cpu 28: unix_release_sock (net/unix/af_unix.c:640) unix_release (net/unix/af_unix.c:1050) sock_close (net/socket.c:659 net/socket.c:1421) __fput (fs/file_table.c:422) __fput_sync (fs/file_table.c:508) __se_sys_close (fs/open.c:1559 fs/open.c:1541) __x64_sys_close (fs/open.c:1541) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) read to 0xffff88867256ddbb of 1 bytes by task 989 on cpu 14: unix_stream_sendmsg (net/unix/af_unix.c:2273) __sock_sendmsg (net/socket.c:730 net/socket.c:745) ____sys_sendmsg (net/socket.c:2584) __sys_sendmmsg (net/socket.c:2638 net/socket.c:2724) __x64_sys_sendmmsg (net/socket.c:2753 net/socket.c:2750 net/socket.c:2750) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) value changed: 0x01 -> 0x03 The line numbers are related to commit dd5a440a31fa ("Linux 6.9-rc7"). Commit e1d09c2c2f57 ("af_unix: Fix data races around sk->sk_shutdown.") addressed a comparable issue in the past regarding sk->sk_shutdown. However, it overlooked resolving this particular data path. This patch only offending unix_stream_sendmsg() function, since the other reads seem to be protected by unix_state_lock() as discussed in Link: https://lore.kernel.org/all/20240508173324.53565-1-kuniyu@amazon.com/ Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Breno Leitao Reviewed-by: Kuniyuki Iwashima Link: https://lore.kernel.org/r/20240509081459.2807828-1-leitao@debian.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/unix/af_unix.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index f66f867049015..995a2a0b208a1 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -2057,7 +2057,7 @@ static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, goto out_err; } - if (sk->sk_shutdown & SEND_SHUTDOWN) + if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN) goto pipe_err; while (sent < len) { -- 2.43.0