From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f171.google.com (mail-pf1-f171.google.com [209.85.210.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4CB04282F39 for ; Tue, 21 Apr 2026 02:51:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776739894; cv=none; b=lH1jPj20akpjI5ItKYFguGy8/iJ1xt6tqS9bJ4q9paTp+sbA2BZubvYSTcJcmD6YQ8kyqOE8U3o8Z2xgDtwiGIM3dZ5ditIyZNWxut/oHytTniBLkGRkU06RWeBnUC3UmtynPVQhUHIEYFhIYC5XjoDMPPyVxfGkiiXAC+ctfd8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776739894; c=relaxed/simple; bh=2GmeUgsVld79fKl1iNI45/UB/0MUWB93JcGKPSGrmas=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uY4MGVdAxJMFvOwS5HLpi51+2YqcoRXxOcevBorKPBsO0L9wG6/dZq2s9oU8o/bJtTwIFGnWUQyXTDdqQhsg5BP/zdpcSOipWcPQDICph8AHtxXNcHqanSUiuAjhWLi48aeHCOZFm7uE04YEMJRXOZA4yr85W3H3xgl/HbB5DhA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=LLT3/GbE; arc=none smtp.client-ip=209.85.210.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="LLT3/GbE" Received: by mail-pf1-f171.google.com with SMTP id d2e1a72fcca58-82f8bf96b46so1792559b3a.2 for ; Mon, 20 Apr 2026 19:51:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1776739893; x=1777344693; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=uJ95cJBTtwe/Q3ftFYdsD7Mm/4M8Wg0mB6kbaOeJjWI=; b=LLT3/GbEJBKqvtCxDzMplMKaq9W7twRUM5LB2NSL7xv//iAAJyEYHyKv4yDcDKymZY LZus+qvZU0Cfbb2K4AYvsdABZd4v8yqv6896Gsw1M73YnVZs2UKcnp1bWeJMaa6F02DA jm/RKyXmBqQTEFnBIkDMZ6GMoF0Sx6w5nX2hR1N1Ry56m+lDOSUxiqGn/i443X3h4M/g snpdoZwhOTXJ8zDB46OfftmEh0boIylpDlKddNIyJBI2f/RrY0zJbiriRE6ZvcJUSNY3 KXj5r9D63om2P66wfRaawNdjJE5NUxAFhV82C3/CVG3uvTzh8DI0iSrS14zZvooF30+n TW5w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776739893; x=1777344693; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=uJ95cJBTtwe/Q3ftFYdsD7Mm/4M8Wg0mB6kbaOeJjWI=; b=iE1dlD9zLWiHg5HVyumt+RWBhEwBIdMbXhbobBRUHDBMi3hNwSkyr4wCry5NNHDeun 2KIrSyiGEIkPMQSHrrmwqdhF2/wxK4npPUQfMMwjheN0qbJNA6xBZ9DfZ6pI2grOo6Gs 72g8C7iYxbdNG169bZayH7m8kCe/5x/Y2rmXQ3RtiHjMlJnMvfKLwkDSrJSB6R1WkVdf 2U2vMSKF1PpScm4NuwsQ0fDQ5qLy6Bzjam3rr7EPgy+qR91FPNRRPtp1fCU5oNivcOeC Vu/VYRG0OLUjm/h/ONGXnSVCX46e9r2M9QDr0MAVkiyfRdqa90Yv/CsdIZ6UEHPyekVI Ahug== X-Forwarded-Encrypted: i=1; AFNElJ8+XsvIgmv2FoseUjgI58hOpbH62x3jqajNwl3ZWNkmmYAiArcncFOyxCD5QBp9B5Nv9pI2k26+accl6l8=@vger.kernel.org X-Gm-Message-State: AOJu0YxlkXeZbrOpCWocMAJoneoAbvlFzVa0h/8+nHMF6phN3CBNJn3C UlXlUHBqFNB0duZyhGFfhFXvB7GrBXPqqbrAztvZYVdnrIPhoiaJNdY4xk5g0mCF X-Gm-Gg: AeBDievfrvx0EyXIUT4HffxJK61sPSIu2Wn4+RZaocJal/QNnQWhbhDytlXEm1lcsER o2W361DBM9lwN6vDW80NlOLNJQ2AYZXpMpYTMkbqzPZl2XhWLiWufYt81BYFhS7N+BLZ9/oXhoy KBR3C/QdsNhoLGdogFNTgJTR6jAA+shQGKclddNZS9+pXWm/Q89UKXwNA2FAnDrRO59fG1sbVYL 3OBSk+bfFTYRghQBLyXNo/fEo2gNwjXxR6y5xcKHqHIFCtsi7/8Ip4SahBN3ISo9qX4Obyipa8G H+xqzb9htyqncOPzw2llyQSx3UdK5PAYq45oenwv6bgDLd09Zuuhb5WmKB8+UEUnOZ1J1NAWdED Au6HaqvSVKfcaddR2TNQAkw1r9NPnfjrRyhemRMtldXeI1iPUu5V84E4oRW4gYARLeSLrUempr8 LxN5edXj4SV6FzkN38TNLGlNiJtehx8pTACezrzd3cF2fXDohsFHoa/BlZ9w== X-Received: by 2002:a05:6a00:aa08:b0:82c:66f2:1226 with SMTP id d2e1a72fcca58-82f8c8e4febmr15916913b3a.38.1776739892565; Mon, 20 Apr 2026 19:51:32 -0700 (PDT) Received: from fedora ([61.74.238.173]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-82f8e9d9a1csm12823502b3a.20.2026.04.20.19.51.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 20 Apr 2026 19:51:32 -0700 (PDT) From: SeungJu Cheon To: luiz.dentz@gmail.com, marcel@holtmann.org Cc: linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, me@brighamcampbell.com, skhan@linuxfoundation.org, linux-kernel-mentees@lists.linux.dev, SeungJu Cheon Subject: [PATCH v2 1/2] Bluetooth: ISO: Fix data-race on dst in iso_sock_connect() Date: Tue, 21 Apr 2026 11:51:21 +0900 Message-ID: <20260421025122.55781-2-suunj1331@gmail.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260421025122.55781-1-suunj1331@gmail.com> References: <20260421025122.55781-1-suunj1331@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit iso_sock_connect() copies the destination address into iso_pi(sk)->dst under lock_sock, then releases the lock and reads it back with bacmp() to decide between the CIS and BIS connect paths: lock_sock(sk); bacpy(&iso_pi(sk)->dst, &sa->iso_bdaddr); iso_pi(sk)->dst_type = sa->iso_bdaddr_type; release_sock(sk); if (bacmp(&iso_pi(sk)->dst, BDADDR_ANY)) // <- no lock held This read after release_sock() races with any concurrent write to iso_pi(sk)->dst on the same socket. Fix by reading the destination address directly from the local sockaddr argument (sa->iso_bdaddr) instead of iso_pi(sk)->dst. Since sa is a function-local argument, reading it requires no locking and avoids the race. This patch addresses only the bacmp() race in iso_sock_connect(); other unprotected iso_pi(sk) accesses are fixed separately in the next patch. KCSAN report: BUG: KCSAN: data-race in memcmp+0x39/0xb0 race at unknown origin, with read to 0xffff8f96ea66dde3 of 1 bytes by task 549 on cpu 1: memcmp+0x39/0xb0 iso_sock_connect+0x275/0xb40 __sys_connect_file+0xbd/0xe0 __sys_connect+0xe0/0x110 __x64_sys_connect+0x40/0x50 x64_sys_call+0xcad/0x1c60 do_syscall_64+0x133/0x590 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x00 -> 0xee Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 549 Comm: iso_race_combin Not tainted 7.0.0-08391-g1d51b370a0f8 #40 PREEMPT(lazy) Fixes: ccf74f2390d6 ("Bluetooth: Add BTPROTO_ISO socket type") Signed-off-by: SeungJu Cheon --- net/bluetooth/iso.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c index be145e2736b7..290a1b9a9daa 100644 --- a/net/bluetooth/iso.c +++ b/net/bluetooth/iso.c @@ -1193,7 +1193,7 @@ static int iso_sock_connect(struct socket *sock, struct sockaddr_unsized *addr, release_sock(sk); - if (bacmp(&iso_pi(sk)->dst, BDADDR_ANY)) + if (bacmp(&sa->iso_bdaddr, BDADDR_ANY)) err = iso_connect_cis(sk); else err = iso_connect_bis(sk); -- 2.52.0