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 EA7B83B1EC0; Sat, 30 May 2026 17:46:45 +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=1780163206; cv=none; b=VNIcrsqI2cqJiKcvOZOWlvZIVg1D3YqXnvlPLx8rml4xc1pEhCxXIVXwwvzgreb1lqizDarwrLkCF+Q12N+w0MJt8oGib2D7krmkFQz3ZyRfIv3giFasKb7QFhIMDEWssDVQ4GZLX7mTwQpgmwDSqolMmuJQEXLniAXs6UuJts8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780163206; c=relaxed/simple; bh=l9gIQo2h2eFCxjsZQdQE8iOeO3klFaAcSC8rUi8FenQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CcXh5QJF+CZCgBAGBMU9C9pQqtxItmgzobIYAnvapy4yotKA8q7Rm093Dn6pBHKzbkSLSPi/pQ19PN6z1kCsmkB8oCxDF0umSZbnDM0j3uURLqYIRui/qhSEqfeSpXfkP+Ej6peAkGLrA9aU3BMpIIFEav0691E7DUgJ4qQD0O4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mp69TBpz; 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="mp69TBpz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D80D1F00893; Sat, 30 May 2026 17:46:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780163205; bh=gsHyBu+U1LFB9EyGEdacvZBaNNBIHXdGMoijWoZgIkc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=mp69TBpzJYbegC+g0x5CK4EoH1MDLp1AnvriHGSBUKRFVy98AReL5gLoweHJJMhjA ftWNG2Hnyxu84SG9O8HjcVXeteEUBoBuOfJpEXoGnNK6hiwi4n986a9DbiehH83hnk LlL/x4+t/MQxYeSjAZwoPvsQM0FhQyxNevtgg6NA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yuhao Jiang , Tyllis Xu Subject: [PATCH 5.15 188/776] ibmasm: fix OOB reads in command_file_write due to missing size checks Date: Sat, 30 May 2026 17:58:22 +0200 Message-ID: <20260530160245.359107578@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160240.228940103@linuxfoundation.org> References: <20260530160240.228940103@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tyllis Xu commit 0eb09f737428e482a32a2e31e5e223f2b35a71d3 upstream. The command_file_write() handler allocates a kernel buffer of exactly count bytes and copies user data into it, but does not validate the buffer against the dot command protocol before passing it to get_dot_command_size() and get_dot_command_timeout(). Since both the allocation size (count) and the header fields (command_size, data_size) are independently user-controlled, an attacker can cause get_dot_command_size() to return a value exceeding the allocation, triggering OOB reads in get_dot_command_timeout() and an out-of-bounds memcpy_toio() that leaks kernel heap memory to the service processor. Fix with two guards: reject writes smaller than sizeof(struct dot_command_header) before allocation, then after copying user data reject commands where the buffer is smaller than the total size declared by the header (sizeof(header) + command_size + data_size). This ensures all subsequent header and payload field accesses stay within the buffer. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Yuhao Jiang Cc: stable@vger.kernel.org Signed-off-by: Tyllis Xu Link: https://patch.msgid.link/20260314165355.548119-1-LivelyCarpet87@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/misc/ibmasm/ibmasmfs.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/misc/ibmasm/ibmasmfs.c +++ b/drivers/misc/ibmasm/ibmasmfs.c @@ -303,6 +303,8 @@ static ssize_t command_file_write(struct return -EINVAL; if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE) return 0; + if (count < sizeof(struct dot_command_header)) + return -EINVAL; if (*offset != 0) return 0; @@ -319,6 +321,11 @@ static ssize_t command_file_write(struct return -EFAULT; } + if (count < get_dot_command_size(cmd->buffer)) { + command_put(cmd); + return -EINVAL; + } + spin_lock_irqsave(&command_data->sp->lock, flags); if (command_data->command) { spin_unlock_irqrestore(&command_data->sp->lock, flags);