{"cve":"CVE-2024-56668","nvd":{"published":"2024-12-27T15:15:26.693","modified":"2026-06-17T08:12:42.037","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Fix qi_batch NULL pointer with nested parent domain\n\nThe qi_batch is allocated when assigning cache tag for a domain. While\nfor nested parent domain, it is missed. Hence, when trying to map pages\nto the nested parent, NULL dereference occurred. Also, there is potential\nmemleak since there is no lock around domain->qi_batch allocation.\n\nTo solve it, add a helper for qi_batch allocation, and call it in both\nthe __cache_tag_assign_domain() and __cache_tag_assign_parent_domain().\n\n  BUG: kernel NULL pointer dereference, address: 0000000000000200\n  #PF: supervisor read access in kernel mode\n  #PF: error_code(0x0000) - not-present page\n  PGD 8104795067 P4D 0\n  Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI\n  CPU: 223 UID: 0 PID: 4357 Comm: qemu-system-x86 Not tainted 6.13.0-rc1-00028-g4b50c3c3b998-dirty #2632\n  Call Trace:\n   ? __die+0x24/0x70\n   ? page_fault_oops+0x80/0x150\n   ? do_user_addr_fault+0x63/0x7b0\n   ? exc_page_fault+0x7c/0x220\n   ? asm_exc_page_fault+0x26/0x30\n   ? cache_tag_flush_range_np+0x13c/0x260\n   intel_iommu_iotlb_sync_map+0x1a/0x30\n   iommu_map+0x61/0xf0\n   batch_to_domain+0x188/0x250\n   iopt_area_fill_domains+0x125/0x320\n   ? rcu_is_watching+0x11/0x50\n   iopt_map_pages+0x63/0x100\n   iopt_map_common.isra.0+0xa7/0x190\n   iopt_map_user_pages+0x6a/0x80\n   iommufd_ioas_map+0xcd/0x1d0\n   iommufd_fops_ioctl+0x118/0x1c0\n   __x64_sys_ioctl+0x93/0xc0\n   do_syscall_64+0x71/0x140\n   entry_SYSCALL_64_after_hwframe+0x76/0x7e","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-401","CWE-476"],"references":["https://git.kernel.org/stable/c/74536f91962d5f6af0a42414773ce61e653c10ee","https://git.kernel.org/stable/c/ffd774c34774fd4cc0e9cf2976595623a6c3a077"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:57:56.913276502+00:00"},"epss":{"cve":"CVE-2024-56668","score":0.00185,"percentile":0.08115,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}