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 C561E44AB6A; Tue, 21 Jul 2026 22:32:25 +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=1784673146; cv=none; b=oSYw/+YqLU56hWcaEkEVFoerZ8UxdDL43b5zr9oEa9gHW3eZWJTC8xveJOkZuBKzSLzcokuYMQugTkjj51Vmksc1nrTGTSm4DBVNeOwOTVqdMNLnBlGy9F5WTabfutkM8liQ+PSuTgkVFRW8mohqdSEgCKIwU+V6zjpx/1ltssU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784673146; c=relaxed/simple; bh=vYHmUumQZtIXJj7e3qkKP/qclsxqLu+lr7FBYqjXP5o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hkk62N35lB1h737tjp07tkJ1Opjjl1D7tEPLKa+4N1VWRvItUl9tHiyaCYKv3+ZuBcSwRrD8Na516JEf7wEjCi53mB9xXutPGsfY7PcepjqrQbDxKRH4UVoTOUvk0q2/PAigv1WEfawEOEVWBOI7/ifpRj5ZF4N34cyU7vIGwPE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ak80GERd; 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="ak80GERd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E2E4D1F000E9; Tue, 21 Jul 2026 22:32:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784673145; bh=P3OZH3RcjMo6sdU339g21CCna/OfMEqGjNHVKpzdhNM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ak80GERdc06nWwRC2xk/Idr/FHzbc6VGjCq17OnCMfBdIGLB1w3oK2sS7b3JrtG3y EIKBJ49sMBBnK634c3JDzfQd+/tkCylYEkKTpYdTAZNLv+pjGXMb2lneGguAMQaFk3 xZTZ4eMPO2LosI22chZJ3he3UvNV3zlXBgw9jBi8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Bryam Vargas , Jonathan Cameron Subject: [PATCH 5.10 035/699] iio: accel: bmc150: clamp the device-reported FIFO frame count Date: Tue, 21 Jul 2026 17:16:34 +0200 Message-ID: <20260721152356.501223035@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152355.667394603@linuxfoundation.org> References: <20260721152355.667394603@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 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bryam Vargas commit ce0e1cae26096fe959a0da5563a6d6d5a801d5fb upstream. __bmc150_accel_fifo_flush() copies the number of samples the device reports in its hardware FIFO into an on-stack buffer u16 buffer[BMC150_ACCEL_FIFO_LENGTH * 3]; which is sized for at most BMC150_ACCEL_FIFO_LENGTH (32) samples. The frame count is read from the FIFO_STATUS register and only masked to its 7 valid bits: count = val & 0x7F; so it can be 0..127. The only other limit applied to it is the optional caller-supplied sample budget: if (samples && count > samples) count = samples; which does not constrain count on the flush-all path (samples == 0), and leaves it well above 32 whenever samples is larger. count samples are then transferred into buffer[]: bmc150_accel_fifo_transfer(data, (u8 *)buffer, count); bmc150_accel_fifo_transfer() reads count * 6 bytes through regmap, so a malfunctioning, malicious or counterfeit accelerometer (or an attacker tampering with the I2C/SPI bus) that reports up to 127 frames writes up to 762 bytes into the 192-byte buffer: a stack out-of-bounds write of up to 570 bytes that clobbers the stack canary, saved registers and the return address. Clamp count to BMC150_ACCEL_FIFO_LENGTH, the number of samples buffer[] is sized for, before the transfer, mirroring the watermark clamp already done in bmc150_accel_set_watermark(). A well-formed flush reports at most BMC150_ACCEL_FIFO_LENGTH frames, so legitimate devices are unaffected. Fixes: 3bbec9773389 ("iio: bmc150_accel: add support for hardware fifo") Cc: stable@vger.kernel.org Signed-off-by: Bryam Vargas Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/accel/bmc150-accel-core.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/iio/accel/bmc150-accel-core.c +++ b/drivers/iio/accel/bmc150-accel-core.c @@ -919,6 +919,8 @@ static int __bmc150_accel_fifo_flush(str if (samples && count > samples) count = samples; + count = min_t(u8, count, BMC150_ACCEL_FIFO_LENGTH); + ret = bmc150_accel_fifo_transfer(data, (u8 *)buffer, count); if (ret) return ret;