This is a note to let you know that I've just added the patch titled iommu/amd: Improve page fault error reporting to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: iommu-amd-improve-page-fault-error-reporting.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 996d120b4de2b0d6b592bd9fbbe6e244b81ab3cc Mon Sep 17 00:00:00 2001 From: Vasant Hegde <vasant.hegde@xxxxxxx> Date: Wed, 15 Feb 2023 05:26:42 +0000 Subject: iommu/amd: Improve page fault error reporting From: Vasant Hegde <vasant.hegde@xxxxxxx> 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@xxxxxxxx> Suggested-by: Joerg Roedel <joro@xxxxxxxxxx> Signed-off-by: Vasant Hegde <vasant.hegde@xxxxxxx> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216865 Link: https://lore.kernel.org/lkml/15d0f9ff-2a56-b3e9-5b45-e6b23300ae3b@xxxxxxxxxxxxx/ Link: https://lore.kernel.org/r/20230215052642.6016-3-vasant.hegde@xxxxxxx Cc: stable@xxxxxxxxxxxxxxx [joro: Edit commit message] Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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) ? Patches currently in stable-queue which might be from vasant.hegde@xxxxxxx are queue-6.1/iommu-amd-improve-page-fault-error-reporting.patch queue-6.1/iommu-amd-do-not-identity-map-v2-capable-device-when.patch