{"cve":"CVE-2025-71067","nvd":{"published":"2026-01-13T16:16:06.077","modified":"2026-06-17T10:03:35.663","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: set dummy blocksize to read boot_block when mounting\n\nWhen mounting, sb->s_blocksize is used to read the boot_block without\nbeing defined or validated. Set a dummy blocksize before attempting to\nread the boot_block.\n\nThe issue can be triggered with the following syz reproducer:\n\n  mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./file1\\x00', 0x0)\n  r4 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x121403, 0x0)\n  ioctl$FS_IOC_SETFLAGS(r4, 0x40081271, &(0x7f0000000980)=0x4000)\n  mount(&(0x7f0000000140)=@nullb, &(0x7f0000000040)='./cgroup\\x00',\n        &(0x7f0000000000)='ntfs3\\x00', 0x2208004, 0x0)\n  syz_clone(0x88200200, 0x0, 0x0, 0x0, 0x0, 0x0)\n\nHere, the ioctl sets the bdev block size to 16384. During mount,\nget_tree_bdev_flags() calls sb_set_blocksize(sb, block_size(bdev)),\nbut since block_size(bdev) > PAGE_SIZE, sb_set_blocksize() leaves\nsb->s_blocksize at zero.\n\nLater, ntfs_init_from_boot() attempts to read the boot_block while\nsb->s_blocksize is still zero, which triggers the bug.\n\n[almaz.alexandrovich@paragon-software.com: changed comment style, added\nreturn value handling]","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/0c9327c8abf9c8f046e45008bb43d94d8ee5c6c5","https://git.kernel.org/stable/c/44a38eb4f7876513db5a1bccde74de9bc4389d43","https://git.kernel.org/stable/c/4fff9a625da958a33191c8553a03283786f9f417","https://git.kernel.org/stable/c/b3c151fe8f543f1a0b8b5df16ce5d97afa5ec85a","https://git.kernel.org/stable/c/d1693a7d5a38acf6424235a6070bcf5b186a360d"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:19:41.481987139+00:00"},"epss":{"cve":"CVE-2025-71067","score":0.00202,"percentile":0.1013,"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."]}