linux-kernel - [PATCH 1/3] iommu/amd: make iommu

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190528182958.3623-2-kevmitch@arista.com>
Date:   Tue, 28 May 2019 11:29:56 -0700
From:   Kevin Mitchell <kevmitch@...sta.com>
To:     Joerg Roedel <joro@...tes.org>
Cc:     iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
        Kevin Mitchell <kevmitch@...sta.com>
Subject: [PATCH 1/3] iommu/amd: make iommu_disable safer

Make it safe to call iommu_disable during early init error conditions
before mmio_base is set, but after the struct amd_iommu has been added
to the amd_iommu_list. For example, this happens if firmware fails to
fill in mmio_phys in the ACPI table leading to a NULL pointer
dereference in iommu_feature_disable.

Signed-off-by: Kevin Mitchell <kevmitch@...sta.com>
---
 drivers/iommu/amd_iommu_init.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index f773792d77fd..3798d7303c99 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -424,6 +424,9 @@ static void iommu_enable(struct amd_iommu *iommu)
 
 static void iommu_disable(struct amd_iommu *iommu)
 {
+	if (!iommu->mmio_base)
+		return;
+
 	/* Disable command buffer */
 	iommu_feature_disable(iommu, CONTROL_CMDBUF_EN);
 
-- 
2.20.1