{"id":"CVE-2024-56568","url":"https://www.cyber-defence.io/tools/cve/CVE-2024-56568","generatedAt":"2026-10-28T08:09:28.984Z","title":"In the Linux kernel, the following vulnerability has been resolved: iommu/arm-smmu: Defer probe of clients after smmu device bound Null pointer dereference occurs due to a race between smmu driver probe and client driver probe, when of_dma_configure()…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu/arm-smmu: Defer probe of clients after smmu device bound\n\nNull pointer dereference occurs due to a race between smmu\ndriver probe and client driver probe, when of_dma_configure()\nfor client is called after the iommu_device_register() for smmu driver\nprobe has executed but before the driver_bound() for smmu driver\nhas been called.\n\nFollowing is how the race occurs:\n\nT1:Smmu device probe\t\tT2: Client device probe\n\nreally_probe()\narm_smmu_device_probe()\niommu_device_register()\n\t\t\t\t\treally_probe()\n\t\t\t\t\tplatform_dma_configure()\n\t\t\t\t\tof_dma_configure()\n\t\t\t\t\tof_dma_configure_id()\n\t\t\t\t\tof_iommu_configure()\n\t\t\t\t\tiommu_probe_device()\n\t\t\t\t\tiommu_init_device()\n\t\t\t\t\tarm_smmu_probe_device()\n\t\t\t\t\tarm_smmu_get_by_fwnode()\n\t\t\t\t\t\tdriver_find_device_by_fwnode()\n\t\t\t\t\t\tdriver_find_device()\n\t\t\t\t\t\tnext_device()\n\t\t\t\t\t\tklist_next()\n\t\t\t\t\t\t    /* null ptr\n\t\t\t\t\t\t       assigned to smmu */\n\t\t\t\t\t/* null ptr dereference\n\t\t\t\t\t   while smmu->streamid_mask */\ndriver_bound()\n\tklist_add_tail()\n\nWhen this null smmu pointer is dereferenced later in\narm_smmu_probe_device, the device crashes.\n\nFix this by deferring the probe of the client device\nuntil the smmu device has bound to the arm smmu driver.\n\n[will: Add comment]","published":"2024-12-27T15:15:16.000Z","lastModified":"2026-06-17T08:12:26.000Z","status":"Modified","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":4.7,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-362","CWE-476"],"affected":["linux/linux kernel"],"epss":{"score":0.00164,"percentile":0.05512,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.16%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/229e6ee43d2a160a1592b83aad620d6027084aad","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4a9485918a042e3114890dfbe19839a1897f8b2c","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5018696b19bc6c021e934a8a59f4b1dd8c0ac9f8","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c2527d07c7e9cda2c6165d5edccf74752baac1b0","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dc02407ea952e20c544a078a6be2e6f008327973","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f8f794f387ad21c4696e5cd0626cb6f8a5f6aea5","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2024-56568","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}