4.4-stable review patch. If anyone has any objections, please let me know.
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[ 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 624e7ff76166..9101be1a6b59 100644 --- a/drivers/iommu/ipmmu-vmsa.c +++ b/drivers/iommu/ipmmu-vmsa.c @@ -372,6 +372,9 @@ 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.