From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-188.mta0.migadu.com (out-188.mta0.migadu.com [91.218.175.188]) (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 B659A343D72 for ; Sat, 14 Mar 2026 19:38:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773517103; cv=none; b=kWLPo3C3pOU/0SHsoc/360iXxQouE0s6gZl4um0PQ+f7xwjkQkyhgK7ovxV43E7eFF6QOURLkr734+L2yqUMP8FuHsLKE7yTD8hLQsZeAoImep1BBbdwvY3St3wQzUpmbt8AKHPZRogquxSOF9QGpOb7tDkzvRWefMPS2xHFGlA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773517103; c=relaxed/simple; bh=BHatjBYmMqWDoVSJLpd9wA/cae++1PKscmXrKmMopf0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Hustd23rIFLQ4pEcUJIkz2gnlPay/gpPIqDnB8e8abJ+XFMq3vwsWKBp0PltjY1ZvuwihHTVtxKgVt2DBPwXZFEy2FOQ8rHAsiIKeAIdWExRlMpJ7bR3C5Cgw2CTmy4QOs4sPmiu7nloSRHC5U8JJSHtXikSXZ+I0IGTL0zUV84= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=A3V02oBy; arc=none smtp.client-ip=91.218.175.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="A3V02oBy" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1773517089; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=1y6+a9hP8kEfCSdJXdEzyPlBatUJQdOrQGIEsbPLPCI=; b=A3V02oBykMZFjJkvFdBTU8UsKKvRxTIgCvPWDEvhTMMlcsLr6W+uFUVAy9doWxfVVoecpR 3I433k6t7LirJaul8QEZuRQQZ4Wa4+bLobvVZnbE6mI1P+qbqJBcb+4UMrBR37ih/ccmpR ni8Qqj9hk9YB7SGvUBLR6Z4sWicitQg= From: Thorsten Blum To: Herbert Xu , "David S. Miller" , Nicolas Ferre , Alexandre Belloni , Claudiu Beznea , Linus Walleij , Ard Biesheuvel Cc: Thorsten Blum , stable@vger.kernel.org, linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] crypto: atmel-sha204a - Fix potential UAF and memory leak in remove path Date: Sat, 14 Mar 2026 20:36:29 +0100 Message-ID: <20260314193627.728469-3-thorsten.blum@linux.dev> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1492; i=thorsten.blum@linux.dev; h=from:subject; bh=BHatjBYmMqWDoVSJLpd9wA/cae++1PKscmXrKmMopf0=; b=owGbwMvMwCUWt7pQ4caZUj3G02pJDJlbd+xedn693PdS6WdfZ39YtTi9wcJ6nYnS65CH37tEm 7jf3XdM7yhlYRDjYpAVU2R5MOvHDN/SmspNJhE7YeawMoEMYeDiFICJpAozMrw+ZHPk7bm2vVHL /lQVZSs9aatY9YTVYf0kfY2SP+tMN+gx/C/Iy6tm5F/vv/FEorbcxh02qbenfN+3y8Hu9VuvmwV imbwA X-Developer-Key: i=thorsten.blum@linux.dev; a=openpgp; fpr=1D60735E8AEF3BE473B69D84733678FD8DFEEAD4 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Unregister the hwrng to prevent new ->read() calls and flush the Atmel I2C workqueue before teardown to prevent a potential UAF if a queued callback runs while the device is being removed. Drop the early return to ensure sysfs entries are removed and ->hwrng.priv is freed, preventing a memory leak. Fixes: da001fb651b0 ("crypto: atmel-i2c - add support for SHA204A random number generator") Cc: stable@vger.kernel.org Signed-off-by: Thorsten Blum --- Changes in v2: - Unregister hwrng to avoid new ->read() calls and then flush the queue - Drop the ->tfm_count check and error logging after flushing (Herbert) - Link to v1: https://lore.kernel.org/lkml/20260221190424.85984-2-thorsten.blum@linux.dev/ --- drivers/crypto/atmel-sha204a.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c index 98d1023007e3..aeadbc9a2759 100644 --- a/drivers/crypto/atmel-sha204a.c +++ b/drivers/crypto/atmel-sha204a.c @@ -191,10 +191,8 @@ static void atmel_sha204a_remove(struct i2c_client *client) { struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client); - if (atomic_read(&i2c_priv->tfm_count)) { - dev_emerg(&client->dev, "Device is busy, will remove it anyhow\n"); - return; - } + devm_hwrng_unregister(&client->dev, &i2c_priv->hwrng); + atmel_i2c_flush_queue(); sysfs_remove_group(&client->dev.kobj, &atmel_sha204a_groups);