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 BC12F29E116; Mon, 4 May 2026 14:19:35 +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=1777904375; cv=none; b=DRjtTKArWZzZf6150cumnP2tOyiXaN2v1W11YDcS71eWnFPAkKxGiAalvoxiO0QEXdtqmhoYvLVV3BLMnJNoAmm3JAJH7sKG5UW2D5SlT0SuaZ+A3at9b8yURVP3UzmNlPhRC6Dp/yxaj6gQRG6A65M39yCcwucH5NJESaAg8IY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777904375; c=relaxed/simple; bh=0Cb0oZugt4VUs4HxWBlTdXHgoIMEE2R+Lrh9Q++geUU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dEd16ozMPEBvT3RRS+TxsHiKqKnhhQ6gGAvWv2q9p4dQWVb/R1FwTtaLPSPYdOpK4swF6sErQE01nPkl3fpQhVdf+d+/TZmGhkib+YXzZd6LjeGuTuNvMjQ5FBqQyQNiuyC6h5sRMS+9Qnif45Q9yknZaJ25KpjXLKtooSsgBls= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ODkZa806; 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="ODkZa806" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0FABCC2BCB8; Mon, 4 May 2026 14:19:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1777904375; bh=0Cb0oZugt4VUs4HxWBlTdXHgoIMEE2R+Lrh9Q++geUU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ODkZa80629DIkSpThs5lf21LOu7aTrmON26fNXeE9ZLsfwtyo+tCLwWSvpMaL1lsD qoZdB7DzPRvwFr2v99sAknN8ed/N/ho6S0+Tq+77gd9jQx7ASts2g1fPCvNkRc3lVM pweOTAJmy+2bzaiE3gHqtVPI77LWDDLtBTRRE/4w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yuhao Jiang , Tyllis Xu Subject: [PATCH 6.12 015/215] ibmasm: fix heap over-read in ibmasm_send_i2o_message() Date: Mon, 4 May 2026 15:50:34 +0200 Message-ID: <20260504135130.730750816@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260504135130.169210693@linuxfoundation.org> References: <20260504135130.169210693@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tyllis Xu commit 9aad71144fa3682cca3837a06c8623016790e7ec upstream. The ibmasm_send_i2o_message() function uses get_dot_command_size() to compute the byte count for memcpy_toio(), but this value is derived from user-controlled fields in the dot_command_header (command_size: u8, data_size: u16) and is never validated against the actual allocation size. A root user can write a small buffer with inflated header fields, causing memcpy_toio() to read up to ~65 KB past the end of the allocation into adjacent kernel heap, which is then forwarded to the service processor over MMIO. Silently clamping the copy size is not sufficient: if the header fields claim a larger size than the buffer, the SP receives a dot command whose own header is inconsistent with the I2O message length, which can cause the SP to desynchronize. Reject such commands outright by returning failure. Validate command_size before calling get_mfa_inbound() to avoid leaking an I2O message frame: reading INBOUND_QUEUE_PORT dequeues a hardware frame from the controller's free pool, and returning without a corresponding set_mfa_inbound() call would permanently exhaust it. Additionally, clamp command_size to I2O_COMMAND_SIZE before the memcpy_toio() so the MMIO write stays within the I2O message frame, consistent with the clamping already performed by outgoing_message_size() for the header field. 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/20260314165805.548293-1-LivelyCarpet87@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/misc/ibmasm/lowlevel.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) --- a/drivers/misc/ibmasm/lowlevel.c +++ b/drivers/misc/ibmasm/lowlevel.c @@ -19,17 +19,21 @@ static struct i2o_header header = I2O_HE int ibmasm_send_i2o_message(struct service_processor *sp) { u32 mfa; - unsigned int command_size; + size_t command_size; struct i2o_message *message; struct command *command = sp->current_command; + command_size = get_dot_command_size(command->buffer); + if (command_size > command->buffer_size) + return 1; + if (command_size > I2O_COMMAND_SIZE) + command_size = I2O_COMMAND_SIZE; + mfa = get_mfa_inbound(sp->base_address); if (!mfa) return 1; - command_size = get_dot_command_size(command->buffer); - header.message_size = outgoing_message_size(command_size); - + header.message_size = outgoing_message_size((unsigned int)command_size); message = get_i2o_message(sp->base_address, mfa); memcpy_toio(&message->header, &header, sizeof(struct i2o_header));