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 901C958FD37 for ; Fri, 11 Sep 2026 20:07:00 +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=1789157223; cv=none; b=eYmacsL+mURedm6JZbgWxE0EVD0KUUHrTb04FsghnhU3i9pcWLA/K0IfjtriT0nNTHJBQOWTWaR+iYN1+xCfZjkg6e5GE2ig+V3NdLqZANW/2Pzkml1MKU5n8cKlIlTwCkNBAhJkpK1rxXvXHeY4mCqJw8Hcyo0VCNNG+7+0cTA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789157223; c=relaxed/simple; bh=UhSxtYLrxfTWN9O190qI38eGKZhFS6EAiyBa05HAWXI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=b8lw7bbeXWzC2ZAhhTjsedZKpnd0v9oZU2g/8R50WQV18IJajdcLym5Qj8/rNICfxQgI+AAdPbcxyOsRL7dRZrG8Am6ydknc/isLeDLAySXw8NQpjq0gFU2gxTcUBr4k8DMGXzpnMMrqEc/ZCMr5TfEqJfbXp0KROp2BLzskybU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=C7YzSCzT; 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="C7YzSCzT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4BD351F00893; Fri, 11 Sep 2026 20:06:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789157219; bh=X4nLSIg7A0MGg1MNV/vMh3qpIa4toAzeq0pwh40tTQM=; h=From:To:Cc:Subject:Date:Reply-To; b=C7YzSCzTrIKUfdpMwr4cOznKLgbzzi9WDEODaoXXFSzCCBcvOlvEQ2SG4m9toqABN h0IOqCiYr82decD7s5OU6vBtU3pATTkb/1/o7KEyv0HjG5ZFIczLPxQuq+aSz0Z+or AzVx9tGRRfhIJbjktpTD7x9Zs3XACWpVwGT9KF1E= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89742: rapidio: mport_cdev: fix use-after-free in dma_req_free() Date: Fri, 11 Sep 2026 21:47:11 +0200 Message-ID: <2026091105-CVE-2026-89742-450e@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=2804; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=pyEg5KzkBlNoYlkgW8bgVp8ACfKTcdfq+A8fpSUmJLc=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLInuTuvVUDs6WtuDKi2XV3pN/UEp5u3AUR/ja2yF/n nZUB23uiGVhEGRikBVTZPmyjefo/opDil6Gtqdh5rAygQxh4OIUgIn4mzMsOOZ1+GCpIk/s3KnM F1mPnb8rHprUwjA/I1345L+PBSu2cxzlzPOPmLlp5iERAA== 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: rapidio: mport_cdev: fix use-after-free in dma_req_free() dma_req_free() acquires buf_mutex through req->map, drops the mapping reference with kref_put(), and then dereferences req->map again to unlock the mutex. If kref_put() drops the last reference, mport_release_mapping() frees the mapping, and the subsequent mutex_unlock() dereferences a freed object. This is a use-after-free. Fix this by caching map and md before kref_put(), clearing req->map while holding buf_mutex, and using the cached md for mutex unlocking. The bug is reachable from userspace via the RapidIO mport character device interface. The Linux kernel CVE team has assigned CVE-2026-89742 to this issue. Affected and fixed versions =========================== Issue introduced in 4.6 with commit e8de370188d098bb49483c287b44925957c3c9b6 and fixed in 6.12.109 with commit 9a9929ec875ff20922c90c96fd544ae8a2a61a8d Issue introduced in 4.6 with commit e8de370188d098bb49483c287b44925957c3c9b6 and fixed in 6.18.50 with commit e6e925cc1f8067c65c7bec3da50a0ead3b3ef4e0 Issue introduced in 4.6 with commit e8de370188d098bb49483c287b44925957c3c9b6 and fixed in 7.2.4 with commit 211c68d817a3d9dc14c0026a59da7cac30f8147e Issue introduced in 4.6 with commit e8de370188d098bb49483c287b44925957c3c9b6 and fixed in 7.3-rc1 with commit 5cbef379a94b161726c5f504598bf4791d45cedc 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-2026-89742 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: drivers/rapidio/devices/rio_mport_cdev.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/9a9929ec875ff20922c90c96fd544ae8a2a61a8d https://git.kernel.org/stable/c/e6e925cc1f8067c65c7bec3da50a0ead3b3ef4e0 https://git.kernel.org/stable/c/211c68d817a3d9dc14c0026a59da7cac30f8147e https://git.kernel.org/stable/c/5cbef379a94b161726c5f504598bf4791d45cedc