From: Vasant Hegde vasant.hegde@amd.com
commit 996d120b4de2b0d6b592bd9fbbe6e244b81ab3cc upstream.
If IOMMU domain for device group is not setup properly then we may hit IOMMU page fault. Current page fault handler assumes that domain is always setup and it will hit NULL pointer derefence (see below sample log).
Lets check whether domain is setup or not and log appropriate message.
Sample log: ---------- amdgpu 0000:00:01.0: amdgpu: SE 1, SH per SE 1, CU per SH 8, active_cu_number 6 BUG: kernel NULL pointer dereference, address: 0000000000000058 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 2 PID: 56 Comm: irq/24-AMD-Vi Not tainted 6.2.0-rc2+ #89 Hardware name: xxx RIP: 0010:report_iommu_fault+0x11/0x90 [...] Call Trace: <TASK> amd_iommu_int_thread+0x60c/0x760 ? __pfx_irq_thread_fn+0x10/0x10 irq_thread_fn+0x1f/0x60 irq_thread+0xea/0x1a0 ? preempt_count_add+0x6a/0xa0 ? __pfx_irq_thread_dtor+0x10/0x10 ? __pfx_irq_thread+0x10/0x10 kthread+0xe9/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2c/0x50 </TASK>
Reported-by: Matt Fagnani matt.fagnani@bell.net Suggested-by: Joerg Roedel joro@8bytes.org Signed-off-by: Vasant Hegde vasant.hegde@amd.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=216865 Link: https://lore.kernel.org/lkml/15d0f9ff-2a56-b3e9-5b45-e6b23300ae3b@leemhuis.i... Link: https://lore.kernel.org/r/20230215052642.6016-3-vasant.hegde@amd.com Cc: stable@vger.kernel.org [joro: Edit commit message] Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iommu/amd/iommu.c | 9 +++++++++ 1 file changed, 9 insertions(+)
--- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -558,6 +558,15 @@ static void amd_iommu_report_page_fault( * prevent logging it. */ if (IS_IOMMU_MEM_TRANSACTION(flags)) { + /* Device not attached to domain properly */ + if (dev_data->domain == NULL) { + pr_err_ratelimited("Event logged [Device not attached to domain properly]\n"); + pr_err_ratelimited(" device=%04x:%02x:%02x.%x domain=0x%04x\n", + iommu->pci_seg->id, PCI_BUS_NUM(devid), PCI_SLOT(devid), + PCI_FUNC(devid), domain_id); + goto out; + } + if (!report_iommu_fault(&dev_data->domain->domain, &pdev->dev, address, IS_WRITE_REQUEST(flags) ?