{"cve":"CVE-2025-38256","nvd":{"published":"2025-07-09T11:15:27.880","modified":"2026-06-17T09:16:29.603","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/rsrc: fix folio unpinning\n\nsyzbot complains about an unmapping failure:\n\n[  108.070381][   T14] kernel BUG at mm/gup.c:71!\n[  108.070502][   T14] Internal error: Oops - BUG: 00000000f2000800 [#1]  SMP\n[  108.123672][   T14] Hardware name: QEMU KVM Virtual Machine, BIOS edk2-20250221-8.fc42 02/21/2025\n[  108.127458][   T14] Workqueue: iou_exit io_ring_exit_work\n[  108.174205][   T14] Call trace:\n[  108.175649][   T14]  sanity_check_pinned_pages+0x7cc/0x7d0 (P)\n[  108.178138][   T14]  unpin_user_page+0x80/0x10c\n[  108.180189][   T14]  io_release_ubuf+0x84/0xf8\n[  108.182196][   T14]  io_free_rsrc_node+0x250/0x57c\n[  108.184345][   T14]  io_rsrc_data_free+0x148/0x298\n[  108.186493][   T14]  io_sqe_buffers_unregister+0x84/0xa0\n[  108.188991][   T14]  io_ring_ctx_free+0x48/0x480\n[  108.191057][   T14]  io_ring_exit_work+0x764/0x7d8\n[  108.193207][   T14]  process_one_work+0x7e8/0x155c\n[  108.195431][   T14]  worker_thread+0x958/0xed8\n[  108.197561][   T14]  kthread+0x5fc/0x75c\n[  108.199362][   T14]  ret_from_fork+0x10/0x20\n\nWe can pin a tail page of a folio, but then io_uring will try to unpin\nthe head page of the folio. While it should be fine in terms of keeping\nthe page actually alive, mm folks say it's wrong and triggers a debug\nwarning. Use unpin_user_folio() instead of unpin_user_page*.\n\n[axboe: adapt to current tree, massage commit message]","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":[],"references":["https://git.kernel.org/stable/c/11e7b7369e655e6131387b174218d7fa9557b3da","https://git.kernel.org/stable/c/53fd75f25b223878b5fff14932e3a22f42b54f77","https://git.kernel.org/stable/c/5afb4bf9fc62d828647647ec31745083637132e4"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:04:28.436527499+00:00"},"epss":{"cve":"CVE-2025-38256","score":0.00165,"percentile":0.05691,"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."]}