CVE-2026-97927
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.
How to fix
- Linux Linuxe58db6c2dce6e453dca26c3a4953002425201880, 05360c6eb8388bb5adac3c439ffb1512de39550a, 5cc48633fb76196b596a449ba1f4f642ad6125ce, cd21f1ff74b1c15077fa3b98e80da3b41055aae4, a9804121d55aaa4319c1cac00b99794aa177dd6a, 785e523b6c1931d802cab9f85912f3e6c7028af1, 8173e051a8acbb4ae6547be0436727944119e0b5, 55a4c98abb9694b067c6a031d11501f06b6b523c or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Linux Linux | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ≤ v < e58db6c2dce6e453dca26c3a4953002425201880, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ≤ v < 05360c6eb8388bb5adac3c439ffb1512de39550a, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ≤ v < 5cc48633fb76196b596a449ba1f4f642ad6125ce, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ≤ v < cd21f1ff74b1c15077fa3b98e80da3b41055aae4, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ≤ v < a9804121d55aaa4319c1cac00b99794aa177dd6a, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ≤ v < 785e523b6c1931d802cab9f85912f3e6c7028af1, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ≤ v < 8173e051a8acbb4ae6547be0436727944119e0b5, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ≤ v < 55a4c98abb9694b067c6a031d11501f06b6b523c, 2.6.12 | e58db6c2dce6e453dca26c3a4953002425201880, 05360c6eb8388bb5adac3c439ffb1512de39550a, 5cc48633fb76196b596a449ba1f4f642ad6125ce, cd21f1ff74b1c15077fa3b98e80da3b41055aae4, a9804121d55aaa4319c1cac00b99794aa177dd6a, 785e523b6c1931d802cab9f85912f3e6c7028af1, 8173e051a8acbb4ae6547be0436727944119e0b5, 55a4c98abb9694b067c6a031d11501f06b6b523c |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.