ntfs: set dummy blocksize to read boot_block when mounting
Published Jan 13, 2026
No CVSS score
EPSS 0.20%
Description
When mounting, sb->s_blocksize is used to read the boot_block without being defined or validated. Set a dummy blocksize before attempting to read the boot_block.
The issue can be triggered with the following syz reproducer:
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./file1\x00', 0x0) r4 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x121403, 0x0) ioctl$FS_IOC_SETFLAGS(r4, 0x40081271, &(0x7f0000000980)=0x4000) mount(&(0x7f0000000140)=@nullb, &(0x7f0000000040)='./cgroup\x00', &(0x7f0000000000)='ntfs3\x00', 0x2208004, 0x0) syz_clone(0x88200200, 0x0, 0x0, 0x0, 0x0, 0x0)
Here, the ioctl sets the bdev block size to 16384. During mount, get_tree_bdev_flags() calls sb_set_blocksize(sb, block_size(bdev)), but since block_size(bdev) > PAGE_SIZE, sb_set_blocksize() leaves sb->s_blocksize at zero.
Later, ntfs_init_from_boot() attempts to read the boot_block while sb->s_blocksize is still zero, which triggers the bug.
[almaz.alexandrovich@paragon-software.com: changed comment style, added return value handling]
Affected products
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- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version
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- Version 5.15StatusaffectedConstraints-
- Version 0StatusunaffectedConstraints<5.15
- Version 6.1.167StatusunaffectedConstraints<=6.1.*
- Version 6.12.64StatusunaffectedConstraints<=6.12.*
- Version 6.18.3StatusunaffectedConstraints<=6.18.*
- Version 6.19StatusunaffectedConstraints<=*
- Version 6.6.120StatusunaffectedConstraints<=6.6.*
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
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| Linux | Linux | affected |
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No data.
No data.
Red Hat Enterprise Linux 10
kernel
Not affected
Red Hat Enterprise Linux 6
kernel
Not affected
Red Hat Enterprise Linux 7
kernel
Not affected
Red Hat Enterprise Linux 7
kernel-rt
Not affected
Red Hat Enterprise Linux 8
kernel
Not affected
Red Hat Enterprise Linux 8
kernel-rt
Not affected
Red Hat Enterprise Linux 9
kernel
Not affected
Red Hat Enterprise Linux 9
kernel-rt
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 6 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 9 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
Jan–Oct 2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.20% (0.00197) | 8.51th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.17% (0.00168) | 6.47th | v5 (v2026.06.15) |
| Jan 14, 2026 | 0.02% (0.00018) | 3.68th | v4 (v2025.03.14) |
No CWE recorded.
References (10)
- https://access.redhat.com/security/cve/CVE-2025-71067 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2429080 Issue Tracking
- 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
- https://lore.kernel.org/linux-cve-announce/2026011323-CVE-2025-71067-9c81@gregkh/T
- https://nvd.nist.gov/vuln/detail/CVE-2025-71067
- https://www.cve.org/CVERecord?id=CVE-2025-71067
Change history (0)
No recorded changes yet.