From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 71EB242B33E for ; Wed, 29 Jul 2026 08:01:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785312118; cv=none; b=nE1Hfc25mPbRfKAtGFasE8QkC7WxwDYg9NHfpeQKAr3MPy1gq9QwySu1eyEFrOSwdsHy93I0FS9jd0JYHIBRW8UeSCthAJGKh6LWyRGPkzYz3xSzkjsEwsXn1Jed3joTEqnze7yjN2Z4mI6ToNd/kvQ/mzYqR/8HAkO+UyiVXx4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785312118; c=relaxed/simple; bh=/XwdC1M9p8d+kBI74bgahfqJ1I6795Viy+54N74Y+P4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=sgxmKC4eJ90hbZPSB8RH90c3+CTwwuncOSegf4YEZrIqNubmqKyYqYBcLLeZQgA+y313v63kN4oxnQ2zfa5aGvmWt8m0WowWqVq8Veydqfjpr7S6J3XHx6H3Y/XoLPzIxv16FZMHaXvy09ti4QiaVQEAHvH12tjsO4vTMfq1+sg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=uSh5HhC2; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="uSh5HhC2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BA6791F000E9; Wed, 29 Jul 2026 08:01:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785312115; bh=DIBN9z0SIGIalmTa5S3qalyrlXub3Rdrd4oaGnGWcvI=; h=From:To:Cc:Subject:Date:Reply-To; b=uSh5HhC2WeEt25LFVhCbFwU3oAF1/OE7qpf1nqTJEloPvJDLsPcRuy6ou9I0j5ecL NKl4iHSOXwYbKzuSg4WOD29MJjLo7KZRWx55UoKc18J8C622EzrWsXsI0GSoexlO9w uKHiOT31yEroi1RaTQTtzGaMhQEBG40p0MkbjH9w= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-64557: Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb() Date: Wed, 29 Jul 2026 10:01:41 +0200 Message-ID: <2026072941-CVE-2026-64557-4d87@gregkh> X-Mailer: git-send-email 2.55.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3806; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=PhVltbvmlbO8TLpXF7KfHjaDSEFcY1A03ES7Y70tR5g=; b=owGbwMvMwCRo6H6F97bub03G02pJDFmZm1OvV8ZKNTBFWs9RVL2xf7bllwvvLt9W37vrVXrF1 G+vO1WfdcSyMAgyMciKKbJ82cZzdH/FIUUvQ9vTMHNYmUCGMHBxCsBEwpQZ5tdyFQUcPdJhecVz 9VHnXUqPdYrTTBjmFywKsH4V13Tpu8ybKy+jApW5W6zuAQA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb() l2cap_sock_new_connection_cb() returned l2cap_pi(sk)->chan after release_sock(parent). Once the parent lock is dropped the newly enqueued child socket sk is reachable via the accept queue, so another task can accept and free it before the callback dereferences sk, resulting in a use-after-free. Rework the ->new_connection() op so the core, rather than the callback, owns the child channel's lifetime. The op now receives a pre-allocated new_chan and returns an errno instead of allocating and returning a channel. l2cap_new_connection() allocates the child channel and links it into the conn list via __l2cap_chan_add() before invoking the callback, so the conn-list reference keeps the channel alive once release_sock(parent) exposes the socket to other tasks. Channel configuration that was duplicated in l2cap_sock_init() and the various new_connection callbacks is consolidated into l2cap_chan_set_defaults(), which now inherits from the parent channel when one is supplied. The Linux kernel CVE team has assigned CVE-2026-64557 to this issue. Affected and fixed versions =========================== Issue introduced in 3.13 with commit 8ffb929098a56939ac71509302eeab5b207bf262 and fixed in 6.1.178 with commit b39298044e5534612511a2ff5de03ba5f6e7a820 Issue introduced in 3.13 with commit 8ffb929098a56939ac71509302eeab5b207bf262 and fixed in 6.6.145 with commit 8c37e4338c801ebb8cee52436c01c41e009f6e87 Issue introduced in 3.13 with commit 8ffb929098a56939ac71509302eeab5b207bf262 and fixed in 6.12.97 with commit 84e718b6a814edc84159361f9f454a4e92ae91ae Issue introduced in 3.13 with commit 8ffb929098a56939ac71509302eeab5b207bf262 and fixed in 6.18.40 with commit 36da806f7fbaee56ad9e81859deec203f9728700 Issue introduced in 3.13 with commit 8ffb929098a56939ac71509302eeab5b207bf262 and fixed in 7.1.5 with commit 733e76e74e406c1d1ddc7369420dd8a47f48bb8a Issue introduced in 3.13 with commit 8ffb929098a56939ac71509302eeab5b207bf262 and fixed in 7.2-rc3 with commit 6fef032af0092ed5ccb767239a9ac1bc38c08a40 Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2026-64557 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: include/net/bluetooth/l2cap.h net/bluetooth/6lowpan.c net/bluetooth/l2cap_core.c net/bluetooth/l2cap_sock.c net/bluetooth/smp.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/b39298044e5534612511a2ff5de03ba5f6e7a820 https://git.kernel.org/stable/c/8c37e4338c801ebb8cee52436c01c41e009f6e87 https://git.kernel.org/stable/c/84e718b6a814edc84159361f9f454a4e92ae91ae https://git.kernel.org/stable/c/36da806f7fbaee56ad9e81859deec203f9728700 https://git.kernel.org/stable/c/733e76e74e406c1d1ddc7369420dd8a47f48bb8a https://git.kernel.org/stable/c/6fef032af0092ed5ccb767239a9ac1bc38c08a40