{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "1866d779d5d2abae59d304e809600ca3ca8d0071"
            },
            {
              "fixed": "17120c5bfb16808509ea18d7fab6027802d93eba"
            },
            {
              "fixed": "e0b7f2922f6bd4c23cbddb7d1fc2bada570d27d1"
            },
            {
              "fixed": "a5129155ca9fba40d77ff19ffead8244e88d6f9c"
            },
            {
              "fixed": "509f4a09bae7f03c87f67f053648874a5e177867"
            },
            {
              "fixed": "928f659a3e3650978a5b4829cc982324f72b474b"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.10.0"
            },
            {
              "fixed": "6.6.157"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.110"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.52"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90139.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: check for NULL root inode in fuse_fill_super_submount\n\nfuse_iget() can return NULL when its inode allocation fails, but\nfuse_fill_super_submount() passed the result straight to get_fuse_inode()\nand decremented fi-\u003enlookup without checking it:\n\n        root = fuse_iget(sb, parent_fi-\u003enodeid, ...);\n        fi = get_fuse_inode(root);\n        fi-\u003enlookup--;\n\nInside fuse_iget() the inode allocation can fail and return NULL.  The\nsubmount root takes the iget5_locked() path, whose alloc_inode() can fail\nunder memory pressure (the auto-submount branch can fail the same way in\nnew_inode() or fuse_alloc_submount_lookup()):\n\n        inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set,\n                             \u0026nodeid);\n        if (!inode)\n                return NULL;\n\nA NULL root makes get_fuse_inode() a container_of() on NULL and the\nnlookup decrement a write to a bogus address, oopsing the mount.  With\nCONFIG_KASAN the following null pointer dereference is reported when the\nroot inode allocation of an auto-submount fails (e.g. under memory\npressure):\n\n==================================================================\nBUG: KASAN: null-ptr-deref in fuse_get_tree_submount+0x656/0x8b0\nRead of size 8 at addr 00000000000002b0 by task ls/942\nCPU: 0 PID: 942 Comm: ls Tainted: G W 6.6 #15\nCall Trace:\n \u003cTASK\u003e\n fuse_get_tree_submount+0x656/0x8b0\n vfs_get_tree+0x48/0x140\n fc_mount+0x13/0x50\n fuse_dentry_automount+0x7a/0xb0\n __traverse_mounts+0xca/0x330\n step_into+0x339/0xac0\n path_lookupat+0xc5/0x2f0\n filename_lookup+0x163/0x2a0\n vfs_statx+0xd5/0x200\n do_statx+0x83/0xd0\n __x64_sys_statx+0xa0/0xc0\n do_syscall_64+0x37/0x90\n entry_SYSCALL_64_after_hwframe+0x78/0xe2\n \u003c/TASK\u003e\n==================================================================\n\nReturn -ENOMEM instead; the caller tears down the partially built\nsuperblock on error, matching the other error returns in this\nfunction.",
  "id": "CVE-2026-90139",
  "modified": "2026-09-19T03:30:52.563335628Z",
  "published": "2026-09-17T16:06:37.179Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/17120c5bfb16808509ea18d7fab6027802d93eba"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/509f4a09bae7f03c87f67f053648874a5e177867"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/928f659a3e3650978a5b4829cc982324f72b474b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a5129155ca9fba40d77ff19ffead8244e88d6f9c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e0b7f2922f6bd4c23cbddb7d1fc2bada570d27d1"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90139.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90139"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "fuse: check for NULL root inode in fuse_fill_super_submount"
}