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 1D1143FF1A8 for ; Fri, 15 May 2026 15:37:11 +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=1778859432; cv=none; b=lTTpHlzqjXaSzkvQdQs0dGHYhtX77xbk0Pe+FQI+5PhEgJbsxrx/cBg2rfHxhNkD4YHa43N966Wg9G90uSHp5ExKi5U+F7OajVXU2T0uILceeVqklhcicDmzSUzJgCSl+ZIptMAYfh8T1BYM2Wrv+lY434MsDnChD14Jfx6JlJ4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778859432; c=relaxed/simple; bh=rh1T7AAxCfApPEuYBc3FTq29G2I6DNdcGclw2UMWM/g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Y8o3o1tg9qKD7aJumGsEMKMgMqYUyVgQYZDPNff91ymATtObnMQcMlOJi0WsgIzyRhDOW7cDamJZRca0N/Y6M41rEJEOpDBXCW2wC4MsPO+lzZgLUZhWy8RMuHF4fyG4kf0Hlo7n6ojgUK2hbEMr8Xwv4Oc1i0MeICR2Jt7ghYs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eGthAw/W; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eGthAw/W" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CB30CC2BCB0; Fri, 15 May 2026 15:37:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778859431; bh=rh1T7AAxCfApPEuYBc3FTq29G2I6DNdcGclw2UMWM/g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eGthAw/WxGZfRjXXwZigCaNM4A6Zss9zsvmeALYT82KJGhguv4epfqVEC60AmRrpX EStGASQhVE23dlAxzKW6b58M1ir1SS1uSJ3+2tV38PqSfV3H5vR43NlGLqXeNBTgoA XtwyEwpvWwPEf1fKN156BTzaYbqBS4dEJ+A3XEJJvE5+0fkVEoEf7tZwtVdSqt6bPl pCQLw2/e714dbEa6wWnJnCbL4U2uHIe0B9z6/pPcP00wFRTyRh/qzRnUqvwFjkzq4D l7ZfqmWJ+vLuvmWoves1hlTwrNm/uU0CCvX9DHlVfv5mO9Ke9pUry63g2kXZdCH88d TqB9YfvIOWUrA== From: Sasha Levin To: stable@vger.kernel.org Cc: Zhenzhong Duan , Lu Baolu , Pranjal Shrivastava , Shuai Xue , Kevin Tian , Jason Gunthorpe , Sasha Levin Subject: [PATCH 6.12.y] iommufd: Fix return value of iommufd_fault_fops_write() Date: Fri, 15 May 2026 11:37:08 -0400 Message-ID: <20260515153708.3323159-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026051240-paralyses-sprawl-a7f1@gregkh> References: <2026051240-paralyses-sprawl-a7f1@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Zhenzhong Duan [ Upstream commit aaca2aa92785a6ab8e3183e7184bca447a99cd76 ] copy_from_user() may return number of bytes failed to copy, we should not pass over this number to user space to cheat that write() succeed. Instead, -EFAULT should be returned. Link: https://patch.msgid.link/r/20260330030755.12856-1-zhenzhong.duan@intel.com Cc: stable@vger.kernel.org Fixes: 07838f7fd529 ("iommufd: Add iommufd fault object") Signed-off-by: Zhenzhong Duan Reviewed-by: Lu Baolu Reviewed-by: Pranjal Shrivastava Reviewed-by: Shuai Xue Reviewed-by: Kevin Tian Signed-off-by: Jason Gunthorpe [ applied identical hunk to drivers/iommu/iommufd/fault.c ] Signed-off-by: Sasha Levin --- drivers/iommu/iommufd/fault.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/iommufd/fault.c b/drivers/iommu/iommufd/fault.c index af39b2379d534..8226e28d79a51 100644 --- a/drivers/iommu/iommufd/fault.c +++ b/drivers/iommu/iommufd/fault.c @@ -317,9 +317,10 @@ static ssize_t iommufd_fault_fops_write(struct file *filep, const char __user *b mutex_lock(&fault->mutex); while (count > done) { - rc = copy_from_user(&response, buf + done, response_size); - if (rc) + if (copy_from_user(&response, buf + done, response_size)) { + rc = -EFAULT; break; + } static_assert((int)IOMMUFD_PAGE_RESP_SUCCESS == (int)IOMMU_PAGE_RESP_SUCCESS); -- 2.53.0