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 F089A46D2B9 for ; Tue, 21 Jul 2026 17:13:55 +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=1784654037; cv=none; b=MSQaUzmw0ITRY/W8QLqh5w7MKVokv7SvQ6pFKFdNPIH/prDnxB7GOSXWHtOF0L9u2zAXRqJR5upfL98RrsJLimGPDnnvh32I4+rhj1ouXOCB0v9W6FAF/a79UHPwAIMjrz1cWHycBtPINq1rj9JWimrROkdjp40gVjvIwuLpW3E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784654037; c=relaxed/simple; bh=/LVutYw7OZVzvpXOMS82SzBIgA831AlAuQnj3jEml74=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sHAKq0Zll8LD4pzH2yZtf5aqBQCUgv/ZRHXjFrtp1w5DASd3pO827hjoqkivZ59ayogS7wzXM4W91Exh/P8W9xAaUQv/Q5DwcBa/yvXmUxPyW6fuHpDOHxpOg0LtnmM+RX/3Ii2CIiSSTyIqPJyw2cLOxCFWWmz7atPViMw+OMg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=i+0NmKMv; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="i+0NmKMv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38F3E1F000E9; Tue, 21 Jul 2026 17:13:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784654035; bh=un6NB/ztRrc9En4iItIouTNBY6LWlhMcXy4di5Xyx+A=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=i+0NmKMvdjitjQj0puK0VhGF8oKKFNHvpcVvr+/ILjqbQWiiI4gKpFyyvU/BgfOIP sE26nqJ/ut3xwhFvkSm0zN+4lRfg9XNlDC9rCURv/lNFRqu01RVzFsdZRmM0IxCZFm SsImb7ZxLyPHJ+YK+rbV/HLceXYH/QGUuHaOx5yCQSKbUjJrMXtQhE6p0CqFVks6gI vnO7LNP3bu/biu0FFOkaj65SV9DopjSrfs6XHLkhGSJ5ZuVhgsrQhRujC7h+znhqQ6 sF1AkMLGYIC0EcjPzFz4R0+6HFlkFR2c0hISgSpclbOI3k+bKhtje1EITc0s6ubech sJHZE21UKE9IQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Nicolin Chen , Pranjal Shrivastava , Kevin Tian , Jason Gunthorpe , Sasha Levin Subject: [PATCH 6.12.y 1/3] iommufd: Reject invalid read count in iommufd_fault_fops_read() Date: Tue, 21 Jul 2026 13:13:51 -0400 Message-ID: <20260721171353.111431-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026071619-canning-snowdrop-2a4d@gregkh> References: <2026071619-canning-snowdrop-2a4d@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: Nicolin Chen [ Upstream commit 47916a54eeb2a9e654512ee609f71bd5b29db702 ] The read count must be large enough to hold one fault or a group's faults. iommufd_fault_fops_read() does not validate the count, but returns 0 as if the read had succeeded while leaving the pending fault in the queue. Return -EINVAL in the undersize cases. Fixes: 07838f7fd529 ("iommufd: Add iommufd fault object") Link: https://patch.msgid.link/r/85c118a606fbedc5c132a1f5ec223a5ba23b92d2.1780343944.git.nicolinc@nvidia.com Cc: stable@vger.kernel.org Signed-off-by: Nicolin Chen Reviewed-by: Pranjal Shrivastava Reviewed-by: Kevin Tian Signed-off-by: Jason Gunthorpe [ sashal: applied to fault.c as 6.12 lacks the eventq.c split ] Signed-off-by: Sasha Levin --- drivers/iommu/iommufd/fault.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/iommu/iommufd/fault.c b/drivers/iommu/iommufd/fault.c index 8226e28d79a510..6048d8a1c8380e 100644 --- a/drivers/iommu/iommufd/fault.c +++ b/drivers/iommu/iommufd/fault.c @@ -273,6 +273,9 @@ static ssize_t iommufd_fault_fops_read(struct file *filep, char __user *buf, if (done >= count || group->fault_count * fault_size > count - done) { iommufd_fault_deliver_restore(fault, group); + /* Read count doesn't fit the first fault group */ + if (done == 0) + rc = -EINVAL; break; } -- 2.53.0