CVE-2024-35957 iommu/vt-d: Fix WARN_ON in iommu probe path
A kernel bug in the Intel IOMMU driver causes a warning and probe failure on certain platforms, leading to a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-35957?
CVE-2024-35957 is a medium-severity denial of service vulnerability in Linux kernel, published on 20 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Fix WARN_ON in iommu probe path
Commit 1a75cc710b95 ("iommu/vt-d: Use rbtree to track iommu probed devices") adds all devices probed by the iommu driver in a rbtree indexed by the source ID of each device. It assumes that each device has a unique source ID. This assumption is incorrect and the VT-d spec doesn't state this requirement either.
The reason for using a rbtree to track devices is to look up the device with PCI bus and devfunc in the paths of handling ATS invalidation time out error and the PRI I/O page faults. Both are PCI ATS feature related.
Only track the devices that have PCI ATS capabilities in the rbtree to avoid unnecessary WARN_ON in the iommu probe path. Otherwise, on some platforms below kernel splat will be displayed and the iommu probe results in failure.
WARNING: CPU: 3 PID: 166 at drivers/iommu/intel/iommu.c:158 intel_iommu_probe_device+0x319/0xd90 Call Trace: <TASK> ? __warn+0x7e/0x180 ? intel_iommu_probe_device+0x319/0xd90 ? report_bug+0x1f8/0x200 ? handle_bug+0x3c/0x70 ? exc_invalid_op+0x18/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? intel_iommu_probe_device+0x319/0xd90 ? debug_mutex_init+0x37/0x50 __iommu_probe_device+0xf2/0x4f0 iommu_probe_device+0x22/0x70 iommu_bus_notifier+0x1e/0x40 notifier_call_chain+0x46/0x150 blocking_notifier_call_chain+0x42/0x60 bus_notify+0x2f/0x50 device_add+0x5ed/0x7e0 platform_device_add+0xf5/0x240 mfd_add_devices+0x3f9/0x500 ? preempt_count_add+0x4c/0xa0 ? up_write+0xa2/0x1b0 ? __debugfs_create_file+0xe3/0x150 intel_lpss_probe+0x49f/0x5b0 ? pci_conf1_write+0xa3/0xf0 intel_lpss_pci_probe+0xcf/0x110 [intel_lpss_pci] pci_device_probe+0x95/0x120 really_probe+0xd9/0x370 ? __pfx___driver_attach+0x10/0x10 __driver_probe_device+0x73/0x150 driver_probe_device+0x19/0xa0 __driver_attach+0xb6/0x180 ? __pfx___driver_attach+0x10/0x10 bus_for_each_dev+0x77/0xd0 bus_add_driver+0x114/0x210 driver_register+0x5b/0x110 ? __pfx_intel_lpss_pci_driver_init+0x10/0x10 [intel_lpss_pci] do_one_initcall+0x57/0x2b0 ? kmalloc_trace+0x21e/0x280 ? do_init_module+0x1e/0x210 do_init_module+0x5f/0x210 load_module+0x1d37/0x1fc0 ? init_module_from_file+0x86/0xd0 init_module_from_file+0x86/0xd0 idempotent_init_module+0x17c/0x230 __x64_sys_finit_module+0x56/0xb0 do_syscall_64+0x6e/0x140 entry_SYSCALL_64_after_hwframe+0x71/0x79
Weakness: CWE-617
Which versions are affected by CVE-2024-35957?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-35957?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-35957 being exploited?
There is no known exploitation of CVE-2024-35957 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2024-35957, GHSA-24w8-46cp-j5f8, UBUNTU-CVE-2024-35957.