iommu/ipmmu-vmsa: Fix crash on early domain free
authorGeert Uytterhoeven <geert+renesas@glider.be>
Wed, 7 Nov 2018 13:18:50 +0000 (14:18 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 13 Dec 2018 08:18:46 +0000 (09:18 +0100)
commitb65fa7b581f8a50ef147055006a7aa28ddb1086d
tree19c2bb4edb81fa1d4f1c1deabbdbb88cad1f225c
parent8fa55f1d1859a6b0d2e6c1606b6d8fa1a9ef63d2
iommu/ipmmu-vmsa: Fix crash on early domain free

[ 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