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CVE PROGRAM SOURCE RECORDUnscored

CVE-2026-97927

ufs: create the root dentry after loading cylinder metadata

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Status
Published
Published
Updated
Assigning organization
Linux

Description

In the Linux kernel, the following vulnerability has been resolved: ufs: create the root dentry after loading cylinder metadata ufs_fill_super() installed sb->s_root before it loaded the cylinder group structures for a writable mount: sb->s_root = d_make_root(inode); ... if (!sb_rdonly(sb)) if (!ufs_read_cylinder_structures(sb)) goto failed; When ufs_read_cylinder_structures() failed, the error path freed the in-core superblock information and set sb->s_fs_info to NULL while sb->s_root stayed installed. get_tree_bdev() then reached deactivate_locked_super(), and because s_root was present, generic_shutdown_super() called sync_filesystem() and the put_super operation. Both dereference UFS_SB(sb), which is now NULL, so a mount that fails only while reading the cylinder groups oopses during teardown. A crafted image whose first cylinder group cannot be read reaches this path. Load the cylinder group metadata first and create the root dentry last, so the superblock is published to the VFS only once it is fully set up. ufs_setup_cstotal() and ufs_read_cylinder_structures() take only the super_block and do not use the root inode, so the reordering is safe.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < e58db6c2dce6e453dca26c3a4953002425201880affected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 05360c6eb8388bb5adac3c439ffb1512de39550aaffected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 5cc48633fb76196b596a449ba1f4f642ad6125ceaffected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < cd21f1ff74b1c15077fa3b98e80da3b41055aae4affected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < a9804121d55aaa4319c1cac00b99794aa177dd6aaffected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 785e523b6c1931d802cab9f85912f3e6c7028af1affected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 8173e051a8acbb4ae6547be0436727944119e0b5affected
  • 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to < 55a4c98abb9694b067c6a031d11501f06b6b523caffected

Linux Linux

Default version status: affected

  • 2.6.12affected
  • 0 to < 2.6.12unaffected
  • 5.10.271 to ≤ 5.10.*unaffected
  • 5.15.222 to ≤ 5.15.*unaffected
  • 6.1.189 to ≤ 6.1.*unaffected
  • 6.6.158 to ≤ 6.6.*unaffected
  • 6.12.111 to ≤ 6.12.*unaffected
  • 6.18.53 to ≤ 6.18.*unaffected
  • 7.2.7 to ≤ 7.2.*unaffected
  • 7.3 to ≤ *unaffected

References