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 6A31C58E2AC for ; Fri, 11 Sep 2026 19:59:14 +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=1789156765; cv=none; b=TVsgDu8GD+fy4ER3d7q9QIBYBfDqkHtm80FOmdIQqPDRvEwa0lIyeMyKOcCWa9KXeFJyLWGo8BaJQlmWMj4hM8VU5tyaBD3I2KrC2Lfs+55Pr5XHHcxfOkSsPZIoXAex5/XwdBQiZS5aSgWSjkN1kGokBla5EDJgb9qicelZ56o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156765; c=relaxed/simple; bh=Wf5PGDClKrl6YjFk4IDAbVDkO0q7HRFC2RdScTtK6XE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=mwVENHobxOmtjghUKAIca0Q+7aSFJBcdG9xfGZvBkZEenfvSKLYTISV+0Fb6V3NydInPp/AMrGuD2VlJgfFKJNnCjpIQanqLf/MUNyoabFt1Md32Ii0Hu2e7kc9IHUU3nZe3aB+Y2urDGZisF4kzlIIL+K6+aW9WJplXSP7qnPg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=VKYCPVcT; 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="VKYCPVcT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 182C71F0089A; Fri, 11 Sep 2026 19:59:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156753; bh=uW9mvdlOLw1I9CRLc+7P2s7514/CrMFTXZnSN/kWYCE=; h=From:To:Cc:Subject:Date:Reply-To; b=VKYCPVcTSF9fZzmExYoVDyFIZ0JRSxRyH0HpKktM4TSsWEpfrYjCaFzuJ2lr75yT+ 9eakP7ta3DlkKLVZwnvQKTyEhRd3uT2TEEefR+Yo4eM79KiaX0HN9ukknt0Vh5MxQJ ByK+VQ7hEECU2VdA4NzU3nZskbxcUcz8YM7ps7h0= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89621: HID: mcp2221: validate report size in mcp2221_raw_event() Date: Fri, 11 Sep 2026 21:45:10 +0200 Message-ID: <2026091137-CVE-2026-89621-e157@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=2843; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=vXEnz6xzKX/9baz1n2+uShH7Zlwe/GixfG9SjVc7Qro=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIgsFn6/ovdQWwPH47un1jsfip8rxafYtE7abJDDlq HTO5TSRjlgWBkEmBlkxRZYv23iO7q84pOhlaHsaZg4rE8gQBi5OAZjItliGBfsNPMtzbJNcQp61 Td5wJZNRyy5pL8N8t8JJc8/9/XT+O0tWwe2oBPVsnx/yAA== 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: HID: mcp2221: validate report size in mcp2221_raw_event() mcp2221_raw_event() never validates the size of incoming HID reports. In the MCP2221_I2C_GET_DATA path it trusts the device-supplied data[3] as the copy length without checking that 4 + data[3] bytes actually exist in the received report. A malicious or misbehaving USB device can send a short report with a large data[3], causing the memcpy to read past the valid report data in the HID transfer buffer and leak uninitialized kernel memory back to userspace through the I2C/SMBus read path. Add a minimum size check at entry and validate that the source range fits within the received report before the copy. The Linux kernel CVE team has assigned CVE-2026-89621 to this issue. Affected and fixed versions =========================== Issue introduced in 5.7 with commit 67a95c21463d066060b0f66d65a75d45bb386ffb and fixed in 6.12.109 with commit bdc6a3af0dd734a326acdb7d6401a3b6a9f4f149 Issue introduced in 5.7 with commit 67a95c21463d066060b0f66d65a75d45bb386ffb and fixed in 6.18.50 with commit 127de5919820f88a9d55e8371ad4ac49f625f4c5 Issue introduced in 5.7 with commit 67a95c21463d066060b0f66d65a75d45bb386ffb and fixed in 7.2.4 with commit 7c18fb36708a97ff6772825cc087b6d537bbf0d5 Issue introduced in 5.7 with commit 67a95c21463d066060b0f66d65a75d45bb386ffb and fixed in 7.3-rc1 with commit 2c9a6998c19503626c57a2267bf279e204113079 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-2026-89621 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/hid/hid-mcp2221.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/bdc6a3af0dd734a326acdb7d6401a3b6a9f4f149 https://git.kernel.org/stable/c/127de5919820f88a9d55e8371ad4ac49f625f4c5 https://git.kernel.org/stable/c/7c18fb36708a97ff6772825cc087b6d537bbf0d5 https://git.kernel.org/stable/c/2c9a6998c19503626c57a2267bf279e204113079