{"cve":"CVE-2025-21933","nvd":{"published":"2025-04-01T16:15:24.143","modified":"2026-06-17T08:44:38.860","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\narm: pgtable: fix NULL pointer dereference issue\n\nWhen update_mmu_cache_range() is called by update_mmu_cache(), the vmf\nparameter is NULL, which will cause a NULL pointer dereference issue in\nadjust_pte():\n\nUnable to handle kernel NULL pointer dereference at virtual address 00000030 when read\nHardware name: Atmel AT91SAM9\nPC is at update_mmu_cache_range+0x1e0/0x278\nLR is at pte_offset_map_rw_nolock+0x18/0x2c\nCall trace:\n update_mmu_cache_range from remove_migration_pte+0x29c/0x2ec\n remove_migration_pte from rmap_walk_file+0xcc/0x130\n rmap_walk_file from remove_migration_ptes+0x90/0xa4\n remove_migration_ptes from migrate_pages_batch+0x6d4/0x858\n migrate_pages_batch from migrate_pages+0x188/0x488\n migrate_pages from compact_zone+0x56c/0x954\n compact_zone from compact_node+0x90/0xf0\n compact_node from kcompactd+0x1d4/0x204\n kcompactd from kthread+0x120/0x12c\n kthread from ret_from_fork+0x14/0x38\nException stack(0xc0d8bfb0 to 0xc0d8bff8)\n\nTo fix it, do not rely on whether 'ptl' is equal to decide whether to hold\nthe pte lock, but decide it by whether CONFIG_SPLIT_PTE_PTLOCKS is\nenabled.  In addition, if two vmas map to the same PTE page, there is no\nneed to hold the pte lock again, otherwise a deadlock will occur.  Just\nadd the need_lock parameter to let adjust_pte() know this information.","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-476"],"references":["https://git.kernel.org/stable/c/91d011efe30aedde067ce6d218d521cf99b162e5","https://git.kernel.org/stable/c/a564ccfe300fa6a065beda06ab7f3c140d6b4d63"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:00:57.946988208+00:00"},"epss":{"cve":"CVE-2025-21933","score":0.00174,"percentile":0.06819,"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."]}