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 344A33ACA5D for ; Tue, 21 Jul 2026 17:12:53 +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=1784653974; cv=none; b=neii+OJVFpEZJdyCEMHCP3a1+LqAAp6ZjIrKdED4lI+6K+rZjhezQV3HHuwr69W64XKCDooUDqC9wEW4cDs7mGKifATn8Wx5NHXEB18w0rc4mdekQqoHA649PixwRjMNfLWPJPM12Tw3aYGJBhPfnLkTtG4Qtwe8sHj7wylKz08= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784653974; c=relaxed/simple; bh=q9loNUDxcWZI1oUmEy7pb5foQQLOwAPHX/FEtOGX6Gg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EIuCbOVyiGg7iI9K0bX1TTbOV9s6OnlHvjWYGyp7AuMsbAAbABIKxdrckb0Cj4O8/a4qThLT8gIuC2hcFWQ7EMuFdwUpwKpBlDuBQ3XpXu2klsUpiE/UsiiExOiIxWvq8KWHsy2HwBj4q09+JzQGceFBihVQeG2+Q2ChmwUStLw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bk4MuhW2; 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="bk4MuhW2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63DAD1F000E9; Tue, 21 Jul 2026 17:12:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784653973; bh=O5rA5V/Nf4o0sX+fbziaVhxucuZ5cEr/z3l4cBh0jVo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bk4MuhW2OlAo969WVXZhTJaijksXGa2Gq5rW70RzZodhNEx34rBFGr9vQ2T0VjaRq jnp8egieRqQDAUMrYY73Jt+Kmu8DfM0NDiyA5Ddu0nU+SD0qysW9s/Fujz48ky8JJJ /WHDSFg8/qqV31S8s+tAKj/AREIc1M/pF1wEGJZzB5G+NYa1Mp6PXFt1E6iki9rrEy 78YVgmYp+tFIw7qGt+73gdcev0DsO4iSV0Uk2vX8wgMReOYhR3TyMtf3sWqC6SNexP keZ4GCwHfcsDQJgMbsG21wf0Pb+96jGbKTenZWrqJCRKj/OOe6xyJDdiPiENyMdmX8 NbPBfmBZH3rSA== From: Sasha Levin To: stable@vger.kernel.org Cc: Nicolin Chen , Pranjal Shrivastava , Kevin Tian , Jason Gunthorpe , Sasha Levin Subject: [PATCH 6.12.y] iommufd: Reject invalid read count in iommufd_fault_fops_read() Date: Tue, 21 Jul 2026 13:12:50 -0400 Message-ID: <20260721171250.107567-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026071602-java-pointing-40af@gregkh> References: <2026071602-java-pointing-40af@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 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