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Unscored CVE-2025-71067 EUVD-2026-2258GHSA-wq7w-gfpq-89g4

ntfs: set dummy blocksize to read boot_block when mounting

Published Jan 13, 2026 · Updated May 11, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: linux Package: linux Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.15 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.8 Package: linux-aws-6.14 Package: linux-aws-6.17 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-6.8 Package: linux-aws-fips Package: linux-azure Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.15 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.8 Package: linux-azure-6.11 Package: linux-azure-6.14 Package: linux-azure-6.17 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-6.8 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.15 Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.14 Package: linux-azure-fde-6.2 Package: linux-azure-fde-6.8 Package: linux-azure-fips Package: linux-azure-nvidia Package: linux-azure-nvidia-6.14 Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.15 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.14 Package: linux-gcp-6.17 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-6.8 Package: linux-gcp-fips Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.15 Package: linux-hwe-5.19 Package: linux-hwe-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.14 Package: linux-hwe-6.17 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-6.8 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-5.15 Package: linux-ibm-6.8 Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-intel-iotg Package: linux-intel-iotg-5.15 Package: linux-kvm Package: linux-lowlatency Package: linux-lowlatency-hwe-5.15 Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.11 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-lowlatency-hwe-6.8 Package: linux-nvidia Package: linux-nvidia-6.11 Package: linux-nvidia-6.17 Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-6.8 Package: linux-nvidia-lowlatency Package: linux-nvidia-tegra Package: linux-nvidia-tegra-5.15 Package: linux-nvidia-tegra-igx Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.11 Package: linux-oem-6.14 Package: linux-oem-6.17 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.15 Package: linux-oracle-5.3 Package: linux-oracle-5.8 Package: linux-oracle-6.14 Package: linux-oracle-6.17 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-raspi Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.14 Package: linux-realtime-6.17 Package: linux-realtime-6.8 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.15 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.14 Package: linux-riscv-6.17 Package: linux-riscv-6.5 Package: linux-riscv-6.8 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx Package: linux-xilinx-zynqmp Platform: Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

In the Linux kernel, the following vulnerability has been resolved:

ntfs: set dummy blocksize to read boot_block when mounting

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

VendorProductAffectedFixed
Linux Linux 5.15 6.1.167

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

Debian

Security tracker ↗
ReleasePackageFixed inAdvisory
Debian 14 linux 6.18.3-1 —
Debian 13 linux 6.12.69-1 DSA-6126-1
Debian 12 linux 6.1.170-1 —

Ubuntu

Security tracker ↗
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 24.04 LTS linux-bluefield 6.8.0-1017.21 —
Ubuntu Nvidia-BlueField 22.04 LTS linux-bluefield No fix yet —
Ubuntu 26.04 LTS linux-vmware No fix yet —
Ubuntu 25.10 linux 6.17.0-22.22 USN-8177-1
Ubuntu 25.10 linux-aws +1 6.17.0-1012.12 USN-8183-2, USN-8183-1
Ubuntu 25.10 linux-azure +1 6.17.0-1013.13 USN-8245-1
Ubuntu 25.10 linux-azure-fde No fix yet —
Ubuntu 25.10 linux-oracle 6.17.0-1011.11 USN-8183-2
Ubuntu 25.10 linux-realtime 6.17.0-1010.11 USN-8177-1
Ubuntu 25.10 linux-riscv 6.17.0-22.22.1 —
Ubuntu 24.04 LTS linux 6.8.0-110.110 USN-8179-1
Ubuntu 24.04 LTS linux-aws 6.8.0-1052.55 USN-8179-1
Ubuntu 24.04 LTS linux-aws-6.17 +1 6.17.0-1012.12~24.04.1 USN-8183-2, USN-8183-1
Ubuntu 24.04 LTS linux-azure 6.8.0-1054.60 USN-8258-1
Ubuntu 24.04 LTS linux-azure-6.17 6.17.0-1013.13~24.04.1 USN-8245-1
Ubuntu 24.04 LTS linux-azure-fde 6.8.0-1058.65 —
Ubuntu 24.04 LTS linux-azure-nvidia 6.8.0-1039.42 —
Ubuntu 24.04 LTS linux-gcp 6.8.0-1054.57 USN-8179-1
Ubuntu 24.04 LTS linux-gke 6.8.0-1050.56 USN-8179-1
Ubuntu 24.04 LTS linux-gkeop 6.8.0-1037.40 USN-8179-1
Ubuntu 24.04 LTS linux-hwe-6.17 6.17.0-22.22~24.04.1 USN-8183-2
Ubuntu 24.04 LTS linux-ibm 6.8.0-1051.51 USN-8179-1
Ubuntu 24.04 LTS linux-lowlatency 6.8.0-110.110.1 USN-8179-1
Ubuntu 24.04 LTS linux-nvidia 6.8.0-1051.54 USN-8185-1
Ubuntu 24.04 LTS linux-nvidia-6.17 6.17.0-1018.18 —
Ubuntu 24.04 LTS linux-nvidia-lowlatency 6.8.0-1051.54.1 USN-8185-2
Ubuntu 24.04 LTS linux-nvidia-tegra 6.8.0-1022.22 USN-8265-1
Ubuntu 24.04 LTS linux-oem-6.17 6.17.0-1020.20 USN-8245-1
Ubuntu 24.04 LTS linux-oracle 6.8.0-1049.50 USN-8203-1
Ubuntu 24.04 LTS linux-oracle-6.17 6.17.0-1011.11~24.04.1 USN-8183-2
Ubuntu 24.04 LTS linux-raspi 6.8.0-1052.56 USN-8179-3
Ubuntu 24.04 LTS linux-riscv +18 No fix yet —
Ubuntu 24.04 LTS linux-riscv-6.17 6.17.0-22.22.1~24.04.1 —
Ubuntu 24.04 LTS linux-xilinx 6.8.0-1028.29 USN-8261-1
Show 10 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 22.04 LTS linux +49 No fix yet —
Ubuntu 22.04 LTS linux-aws-6.8 6.8.0-1052.55~22.04.1 USN-8179-1
Ubuntu 22.04 LTS linux-azure-6.8 6.8.0-1059.65~22.04.1 USN-8440-1
Ubuntu 22.04 LTS linux-azure-fde-6.8 6.8.0-1058.65~22.04.1 —
Ubuntu 22.04 LTS linux-gcp-6.8 6.8.0-1054.57~22.04.1 USN-8179-4
Ubuntu 22.04 LTS linux-hwe-6.8 +1 6.8.0-110.110~22.04.1 USN-8179-3
Ubuntu 22.04 LTS linux-ibm-6.8 6.8.0-1051.51~22.04.1 USN-8179-3
Ubuntu 22.04 LTS linux-lowlatency-hwe-6.8 6.8.0-110.110.1~22.04.1 USN-8179-1
Ubuntu 22.04 LTS linux-nvidia-6.8 6.8.0-1051.54~22.04.1 USN-8185-1
Ubuntu 22.04 LTS linux-oracle-6.8 6.8.0-1049.50~22.04.1 USN-8203-1
Ubuntu 20.04 LTS linux-gke +28 No fix yet —
Ubuntu 18.04 LTS linux-gcp +14 No fix yet —
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-raspi-realtime 6.8.0-2042.43 USN-8204-1
Ubuntu Pro Realtime 24.04 LTS linux-realtime 6.8.1-1047.48 USN-8184-1
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.14 No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.17 6.17.0-1010.11~24.04.1 USN-8177-2
Ubuntu Pro Realtime 22.04 LTS linux-realtime +1 No fix yet —
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1047.48~22.04.1 USN-8184-1
Ubuntu Pro FIPS-updates 24.04 LTS linux-aws-fips 6.8.0-1052.55+fips1 USN-8179-2
Ubuntu Pro FIPS-updates 24.04 LTS linux-azure-fips 6.8.0-1053.59+fips1 —
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips 6.8.0-110.110+fips2 USN-8179-2
Ubuntu Pro FIPS-updates 24.04 LTS linux-gcp-fips 6.8.0-1054.57+fips1 USN-8179-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS-preview 22.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro 20.04 LTS linux-aws-5.15 +10 No fix yet —

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 kernel-livepatch-6.12.64-87.122 +1 1:1.0-0.amzn2023 ALAS2023-2026-1681, ALAS2023-2026-1423
Amazon Linux 2023 perf +14 1:6.1.168-202.320.amzn2023 ALAS2023-2026-1681
Amazon Linux 2023 perf6.12 +14 1:6.12.64-87.122.amzn2023 ALAS2023-2026-1423

Advisories 22

References