{"cve":"CVE-2026-72193","nvd":{"published":"2026-08-15T06:21:37.797","modified":"2026-08-17T06:18:19.947","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nntfs3: cap RESTART_TABLE free-chain walker at rt->used\n\nA crafted NTFS3 disk image triggers an in-kernel infinite loop at\nmount time, hanging the mounting thread and firing the soft-lockup\nwatchdog within ~22s on multi-CPU hosts (panic with\nkernel.softlockup_panic=1).  The bug is reachable from desktop USB\nauto-mount on distributions where udisks2 routes the NTFS signature\nto the in-tree ntfs3 driver (Arch family and an increasing fraction\nof Fedora / openSUSE / RHEL deployments); CAP_SYS_ADMIN-class manual\nmount elsewhere.\n\ncheck_rstbl()'s second walker iterates the free-entry singly-linked\nlist headed by rt->first_free with no upper bound on iteration count:\n\n  for (off = ff; off;) {\n      if (off == RESTART_ENTRY_ALLOCATED)\n          return false;\n      off = le32_to_cpu(*(__le32 *)Add2Ptr(rt, off));\n      if (off > ts - sizeof(__le32))\n          return false;\n  }\n\nThe existing guards cover three exits: end-of-list (off == 0), the\nin-use marker (off == RESTART_ENTRY_ALLOCATED), and out-of-bounds\n(off > ts - sizeof(__le32)).  None of the three prevents an\nin-bounds cycle.\n\nA crafted on-disk RESTART_TABLE whose free chain contains a\nself-loop or A->B->A cycle whose offsets satisfy:\n\n  - in range [sizeof(struct RESTART_TABLE), ts - sizeof(__le32)]\n  - (off - sizeof(struct RESTART_TABLE)) % rsize == 0\n\npasses all existing guards and spins the mount-time thread forever.\nReproduced in UML by hand-forging a 2 MB NTFS3 image whose journal\nRESTART_TABLE first_free = 0x18 and whose entry at offset 0x18\nstores 0x18 as its next pointer; mount of the forged image with\nthe in-tree ntfs3 driver never returns.\n\nBound the walker by rt->used.  Each entry on a legitimate free\nchain is unique, and the total slot count is ne = le16_to_cpu\n(rt->used).  A traversal that visits more than ne slots is by\nconstruction malformed; reject it as a corrupt RESTART_TABLE.\n\nAfter this patch, mount of the forged image returns with -EINVAL\nand a log_replay failure message, and mkntfs-produced legitimate\nimages mount cleanly (verified in the same UML harness).","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/0fad25687d4d3fa1fdd313d31b9cb5817c425029","https://git.kernel.org/stable/c/29b86dbe88cbbef53bb9aaec2e279359f8c450f8","https://git.kernel.org/stable/c/7972df425687daa70d971fe6ed415e78683133dd","https://git.kernel.org/stable/c/7ac4c86915c24c208a0f0611b71d9676686fe756","https://git.kernel.org/stable/c/8128bec895075253c779d67afdc90ae513265fca"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:48:17.459049833+00:00"},"epss":{"cve":"CVE-2026-72193","score":0.00215,"percentile":0.11847,"date":"2026-11-01"},"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."]}