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 3EA00583AD0 for ; Fri, 11 Sep 2026 19:54:08 +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=1789156459; cv=none; b=pP+MrBVkujhSpccJcJvi3YnewXczMEloqG/Ohr93V9yXrQJ2EOTP+U3pMdGlgE2v6ss8+6SChlg4WLpgkWB55MW/gtwfYjpuCceDl8Lo7mbYBNh2sIiS8PYqJMzXxcfW/deCDmkbabfQSpXeyDVNQHsKSEsqKDrcI840dN8/YEg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156459; c=relaxed/simple; bh=L6oCq3OhxWosTpMJSg91wYUL19cV0ERjTY1PEEhms9c=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=k2IUva3cvcsIpvdVh3RO0NXljHqr+RJCtYLvfhIXHzrtxqUl8vyfbMv2XdVEERNqWuXOZnU1QMeMyC3n5XJ0uMR8dpAJuIgYCuwvVFJY96bQyCyYYo5wjpY8o7xaxO11vM5RBQdVhurot2UHFsdzV/r39LA8MKqV7ixbgK1Zwlo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=u43a5gXO; 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="u43a5gXO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5D9E71F00899; Fri, 11 Sep 2026 19:54:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156446; bh=r0eCi9m7aNBxggv55aQcVpQa/Cza2dG+X7JTgqS6BrY=; h=From:To:Cc:Subject:Date:Reply-To; b=u43a5gXOU7tHTyyt4i8i4ZNcfVdyq0pxnHIu1oihylGs9R2tpiJkKERXiUYkOb6d7 Rkbuwwa5L5qs9n+1ogByV6AaBMOJ1hM5WYafiS3XrcQtI+QNHVEdUmEYaJ0saXuhqx rgVWMt5FeovtA4J5gEQw3FtPIknnvJEvxV9jfTKw= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89476: sctp: fix stream->outcnt underflow on duplicate RECONF responses Date: Fri, 11 Sep 2026 21:42:45 +0200 Message-ID: <2026091104-CVE-2026-89476-1178@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=2655; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=bYQ1VzBcuA2yTRcQkXAPDO1aU8sbmF4EeqBg2ogUvUo=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIgM4xZprbpsc7f9TcC282/f2gfdbmY0EwpZ/5lzhH Rm/9veejlgWBkEmBlkxRZYv23iO7q84pOhlaHsaZg4rE8gQBi5OAZjIa0OG+V7O2Ytq7Lec2uBz uIdT8sXsS+smzWWYHy3W3Lni5K4JXenhQXcELxvpPWh6AAA= 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: sctp: fix stream->outcnt underflow on duplicate RECONF responses A cached RECONF chunk may contain more than one request parameter. A duplicate response can therefore find and process the same ADD_OUT request again while another parameter is still outstanding, rolling back outcnt twice and possibly underflowing it. Track outstanding request types as bits and clear each bit after its first response. Later responses for the same request are then ignored. The Linux kernel CVE team has assigned CVE-2026-89476 to this issue. Affected and fixed versions =========================== Issue introduced in 4.12 with commit 11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 and fixed in 6.12.109 with commit 2d867663c563e8009257b9edf9c8ec75d9bbf19a Issue introduced in 4.12 with commit 11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 and fixed in 6.18.50 with commit d02a5794c3deedcb8476d017fcee2b7aaedab2e1 Issue introduced in 4.12 with commit 11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 and fixed in 7.2.4 with commit 8320cbd81bc21a1ca6ebdf70ad610ebc5ef1bd68 Issue introduced in 4.12 with commit 11ae76e67a179f25ae8f772d62a7ddf717b1cdf3 and fixed in 7.3-rc1 with commit 3faf13aff243ca9f78d08b1a2956ef5a6fc77b6e 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-2026-89476 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/sctp/structs.h net/sctp/stream.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/2d867663c563e8009257b9edf9c8ec75d9bbf19a https://git.kernel.org/stable/c/d02a5794c3deedcb8476d017fcee2b7aaedab2e1 https://git.kernel.org/stable/c/8320cbd81bc21a1ca6ebdf70ad610ebc5ef1bd68 https://git.kernel.org/stable/c/3faf13aff243ca9f78d08b1a2956ef5a6fc77b6e