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 85D6948FF69 for ; Fri, 25 Sep 2026 10:24:46 +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=1790331887; cv=none; b=rmSEcu1SmOu7kMatTBMpOq6mjZuYHEr1wvxZV/N08SvEIX5TSOboMV9YDMxXe63ZmBE5bH7BFxuaxMU3fzuLLLyj1LZq7mBC6uZQwRLL0YCG8U1ZVIoCBSaqbdwd7kbMkZFyaBwHakjUIPgzoOdLYCgDTsQX60d+K37RIUfAFYM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790331887; c=relaxed/simple; bh=JRpNAEdVQJYyDVrRS6cGN0v192BqiRIBvzn8nZemoCQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=h+21BQACtm8GmTHloy4x7l3tHBq1djRm6rQN2vEXn4bLIPhQnNukY4FNCZfg9KAxkprOPej8CuF3SxV/aLy1/Z+o+O/aBvra5XEizSQ46mcXMb45W+U5AyvqzG4TFVVzjdgsV2pAPv/agHFKnYXKGGYrFAGGipRPSQM2AJcYnDY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=tnQAMmhi; 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="tnQAMmhi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C7EE01F000FF; Fri, 25 Sep 2026 10:24:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790331886; bh=pSu0zLVc7VVYmSnzPAClXMYyuhMikfMxzLz869Bcxi8=; h=From:To:Cc:Subject:Date:Reply-To; b=tnQAMmhiGoMG+Jh6ATWVVbqZwzGvInU6dbs6nWqWak/6G62jWkVgpPeHOJR6+3rAQ d9VMUhoJhgSzV6+C+MM8NnVHqTQaeQz1mNFerWDcM3RHL2cB3HWsc7M5kPIVNIK+R1 2k668SuMJSzkGgs1bUCyzdDZExTp2VYlhq48Xqoc= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-97566: mptcp: pm: kernel: drop pending ADD_ADDR when removing ID0 Date: Fri, 25 Sep 2026 12:22:26 +0200 Message-ID: <2026092553-CVE-2026-97566-c577@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=3113; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=SAdWCFPq+vDkfHEIDYoQ24wb9s+uou6W7ZVMYHI6GXk=; b=owGbwMvMwCRo6H6F97bub03G02pJDFnbvB0vOglK6VTdaK8S+unYeO3blDm31VTWNYvM5+VKY FLw42DsiGVhEGRikBVTZPmyjefo/opDil6Gtqdh5rAygQxh4OIUgIl8rmVYsOTk/3fLDO7O0JBc xfhyldaJhPKuDwxzeGdzNE9ZoB19UCj4hs3RB5bX93ScBgA= 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: mptcp: pm: kernel: drop pending ADD_ADDR when removing ID0 The in-kernel MPTCP path manager can leave a stale ADD_ADDR announcement entry alive when removing the id 0 endpoint. This happens because the id 0 removal path does not tear down pending announcements, unlike the non-zero id path. When the PM later reselects id 0 after adding another signal endpoint, it finds the stale anno_list entry and hits WARN_ON_ONCE(mptcp_pm_is_kernel()) in mptcp_pm_announced_alloc(). Root cause: asymmetry between removal paths. - Non-zero id path: mptcp_nl_remove_subflow_and_signal_addr() calls mptcp_pm_remove_announced() to clean up. - Id 0 path: mptcp_nl_remove_id_zero_address() skips cleanup entirely. Fix by making the id 0 path symmetric: call mptcp_pm_announced_remove() and decrement add_addr_signaled before queuing the RM_ADDR. Subtle detail: signal endpoints are stored in anno_list with port 0, but msk_local carries the connection's local port. In other words, entries linked to ID0 paths should have port == 0. A follow-up patch will ensure that. mptcp_pm_announced_remove() uses use_port=true for comparison. So clear the port before the lookup. The Linux kernel CVE team has assigned CVE-2026-97566 to this issue. Affected and fixed versions =========================== Issue introduced in 5.13 with commit 740d798e8767d8a449902b1a1bbc70facfce19b5 and fixed in 6.18.53 with commit d4a67a880654e1bfe318a31bea0bdbb026a09ade Issue introduced in 5.13 with commit 740d798e8767d8a449902b1a1bbc70facfce19b5 and fixed in 7.2.7 with commit 545616b4e7325be3c61fc082538cb06d14f7b1db Issue introduced in 5.13 with commit 740d798e8767d8a449902b1a1bbc70facfce19b5 and fixed in 7.3-rc3 with commit 2ac7d6e620764f1fc79eb4edd3610a7a661981ca 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-2026-97566 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: net/mptcp/pm_kernel.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/d4a67a880654e1bfe318a31bea0bdbb026a09ade https://git.kernel.org/stable/c/545616b4e7325be3c61fc082538cb06d14f7b1db https://git.kernel.org/stable/c/2ac7d6e620764f1fc79eb4edd3610a7a661981ca