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 86D2058F09D for ; Fri, 11 Sep 2026 20:05:37 +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=1789157141; cv=none; b=eD/xOrTHbia7x/fq2iYOb+I/mkUdnk0eTzTtyBYr2RKnISI14scgZB4uK2DWvY+5dT6G0tmZvEP0KzAelfqcG26mK7jmJf6vvuAc1Cw3u1kMMu6sMMe7rAOBgU2JgGuZ+rAas8dEa6pulWnKJKm5cpfJq6Uli5gKJeFs7WM+MMo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789157141; c=relaxed/simple; bh=tnVo85j8Gh0547VvtzTCD40bql+Rd0LPsHKWL2O5+UQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=XKRciq2sWRDKBoQlvkgGXn0F8dy5qOJk5d0aL9LXhqQLjY6t6Fh0GdtgiRgfE6dT54ZsWZoPgzdlaY37P93E0AsUs2M4k2/isCC8iIXHh7teyGRKqz+yw9hu9CTqE8SCUmg/8H9bGIh/SvqB8BFlNrqAMQCEFzRq2pJx3/lBWNM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=B6FtniOy; 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="B6FtniOy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 381E91F00898; Fri, 11 Sep 2026 20:05:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789157133; bh=mtSbl8C513eKESr2ztYoBQVjQViKevuB29l5zTO4GSM=; h=From:To:Cc:Subject:Date:Reply-To; b=B6FtniOyUZK8Dpy+2iNW8E0++emFQhQWhCUYyP/YVNGMFRZcGdC5jKLf5+jtpa+3/ j19UDPqeKQDT55xhl3z0zOihZY8uLpIlkYSpMjXAeovVe5qZ/HU90913qYDVr6/yrY 8YYqTpQ+kTafKsJwWKT0N79DWfJpsi+mZAXmmiok= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89748: tracing: Fix retry exhaustion in simple ring buffer reader swap Date: Fri, 11 Sep 2026 21:47:17 +0200 Message-ID: <2026091106-CVE-2026-89748-ec03@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=2451; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=IsB8sN5c6n6IZVQlV9NetOOUgordzlJqe/MbpO5WlAc=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIvum7Y/6Mf1Vi/aK7wLVu68u76m3+hj7UZZj2YGDP ROnLJvzryOWhUGQiUFWTJHlyzaeo/srDil6GdqehpnDygQyhIGLUwAmEnGEYZ51vdLnO7eTthn2 K2msFdvv5WsitBAo+rXiGtehW6KWeoW/WwMe37VTK3sDAA== 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: tracing: Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. The current !retry test reverses both outcomes. It returns an error after a successful final replacement, leaving the link update complete but the reader bookkeeping unfinished. After a failed final replacement, it falls through and updates the head and reader pointers as though the replacement succeeded, which can corrupt the ring. Treat only a negative counter as exhaustion and return the documented -EBUSY error. The Linux kernel CVE team has assigned CVE-2026-89748 to this issue. Affected and fixed versions =========================== Issue introduced in 7.1 with commit 34e5b958bdad0f9cf16306368bbc2dc5b2a50143 and fixed in 7.2.4 with commit df02489aa3aa1834659f0d20c89f7d212047d268 Issue introduced in 7.1 with commit 34e5b958bdad0f9cf16306368bbc2dc5b2a50143 and fixed in 7.3-rc1 with commit e0d3aed7b12cf37b74c7cc5265073d0263b49cde 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-2026-89748 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: kernel/trace/simple_ring_buffer.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/df02489aa3aa1834659f0d20c89f7d212047d268 https://git.kernel.org/stable/c/e0d3aed7b12cf37b74c7cc5265073d0263b49cde