From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B50DD34F483; Mon, 4 May 2026 14:07:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777903662; cv=none; b=aWJjBRYSi5N7PuT5Bcehowd22UPDlt0BPhrjhJZQKbuZjv0KL8tnR2TvfBZkou/EFQNyN97tQAvOTSgUQfGpfKn9SCR2NW4wjwjC7Yv8AcdclBPHQ+avH0NzkHQKr1GZA0HobOiEpbbhSgJUrheV/HtpslEIuJgSdQGX1r/TbYg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777903662; c=relaxed/simple; bh=Da1w/8nB0VJc57jkULUCi77d8/fH7chdLR+kUaKJY/Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bRIic13dG8CqA+GYrw13NuGv70fC1GV5T1vtu1oACxm8GpT0ize7MEU3DiRNzKtf/VOyI9SVFSllDrM1Ne4VZOvStY4h9rCHYTvg/Ir2A2jJXRuVgPa02g2KSdHm2rwkXsN3Au9tePnBllwJQHRdSomkkSTX8AgSDlkMwB9nO68= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JuiW9gpn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="JuiW9gpn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B49DC2BCB8; Mon, 4 May 2026 14:07:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1777903662; bh=Da1w/8nB0VJc57jkULUCi77d8/fH7chdLR+kUaKJY/Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JuiW9gpnQHcCkpitb2qQpLltVq47H7sIHnHLuLzUiq1cF2tGvN/wMg3oT+9wpqi6t jY/r8jYrrIpU+WGnQCpkSKAMNKt4CiBzdSAKf3fht5bwbpd4KgQJfXbEEcGyycDb+1 FISjYCDR1jCCFNJbCab30/AdmuFxPKVkQ3WaK5t0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yuhao Jiang , Tyllis Xu Subject: [PATCH 6.18 014/275] ibmasm: fix OOB reads in command_file_write due to missing size checks Date: Mon, 4 May 2026 15:49:14 +0200 Message-ID: <20260504135143.469252304@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260504135142.929052779@linuxfoundation.org> References: <20260504135142.929052779@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-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);