[PATCH 4.14 04/67] iommu/ipmmu-vmsa: Fix crash on early domain free

Greg Kroah-Hartman
2018-12-11T16:09:31Z

[ Upstream commit e5b78f2e349eef5d4fca5dc1cf5a3b4b2cc27abd ]

If iommu_ops.add_device() fails, iommu_ops.domain_free() is still
called, leading to a crash, as the domain was only partially
initialized:

ipmmu-vmsa e67b0000.mmu: Cannot accommodate DMA translation for IOMMU page tables
sata_rcar ee300000.sata: Unable to initialize IPMMU context
iommu: Failed to add device ee300000.sata to group 0: -22
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000038
...
Call trace:
ipmmu_domain_free+0x1c/0xa0
iommu_group_release+0x48/0x68
kobject_put+0x74/0xe8
kobject_del.part.0+0x3c/0x50
kobject_put+0x60/0xe8
iommu_group_get_for_dev+0xa8/0x1f0
ipmmu_add_device+0x1c/0x40
of_iommu_configure+0x118/0x190

Fix this by checking if the domain's context already exists, before
trying to destroy it.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Fixes: d25a2a16f0889 ('iommu: Add driver for Renesas VMSA-compatible IPMMU')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/iommu/ipmmu-vmsa.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
index 5d0ba5f644c4..777aff1f549f 100644
--- a/drivers/iommu/ipmmu-vmsa.c
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -424,6 +424,9 @@ static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)

static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
{
+ if (!domain->mmu)
+ return;
+
/*
* Disable the context. Flush the TLB as required when modifying the
* context registers.
--
2.19.1