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.
[[email protected]: changed comment style, added return value handling]
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Debian | — | Upgrade linux-6.1Upgrade linux | May 3, 2026 | May 3, 2026 |
| Ubuntu | — | Upgrade linux-image-gcp-64k-6.17Upgrade linux-image-gke-64kUpgrade linux-image-aws-64k-lts-24.04Upgrade linux-image-gcp-fipsUpgrade linux-image-generic-64k-6.17Upgrade linux-image-oracle-64k-6.8Upgrade linux-image-aws-64k-6.17Upgrade linux-image-6.8.0-1051-nvidia-lowlatencyUpgrade linux-image-gcp-64kUpgrade linux-image-generic-64k-6.8Upgrade linux-image-aws-fipsUpgrade linux-image-nvidia-tegra-rtUpgrade linux-image-realtime-hwe-24.04Upgrade linux-image-6.8.0-1052-aws-64kUpgrade linux-image-azure-fipsUpgrade linux-image-6.17.0-1013-azureUpgrade linux-image-6.17.0-22-genericUpgrade linux-image-6.8.0-1052-awsUpgrade linux-image-xilinx-6.8Upgrade linux-image-6.8.0-1054-azureUpgrade linux-image-realtime-6.8.1Upgrade linux-image-fipsUpgrade linux-image-oracle-6.17Upgrade linux-image-lowlatencyUpgrade linux-image-nvidia-64k-6.8Upgrade linux-image-raspi-realtime-6.8Upgrade linux-image-generic-64k-hwe-24.04Upgrade linux-image-nvidia-6.8Upgrade linux-image-6.8.0-110-lowlatencyUpgrade linux-image-aws-64k-6.8Upgrade linux-image-generic-lpaeUpgrade linux-image-nvidia-lowlatencyUpgrade linux-image-6.8.0-2042-raspi-realtimeUpgrade linux-image-aws-6.8Upgrade linux-image-oracle-64k-6.17Upgrade linux-image-6.17.0-1012-gcpUpgrade linux-image-gke-64k-6.8Upgrade linux-image-lowlatency-hwe-22.04Upgrade linux-image-nvidia-lowlatency-64kUpgrade linux-image-6.8.0-1022-nvidia-tegraUpgrade linux-image-6.17.0-1011-oracle-64kUpgrade linux-image-6.17.0-22-generic-64kUpgrade linux-image-oem-6.17Upgrade linux-image-azure-lts-24.04Upgrade linux-image-kvmUpgrade linux-image-gcp-6.17Upgrade linux-image-6.8.0-1029-xilinxUpgrade linux-image-nvidia-tegra-6.8Upgrade linux-image-oracle-64k-lts-24.04Upgrade linux-image-ibm-classicUpgrade linux-image-6.8.0-1052-aws-fipsUpgrade linux-image-6.17.0-1014-raspiUpgrade linux-image-6.8.1-1047-realtimeUpgrade linux-image-raspiUpgrade linux-image-6.8.0-1051-nvidia-lowlatency-64kUpgrade linux-image-aws-fips-6.8Upgrade linux-image-oem-22.04aUpgrade linux-image-oracle-6.8Upgrade linux-image-nvidia-64k-hwe-22.04Upgrade linux-image-raspi-6.8Upgrade linux-image-awsUpgrade linux-image-6.8.0-110-genericUpgrade linux-image-azure-6.17Upgrade linux-image-gcp-64k-lts-24.04Upgrade linux-image-generic-6.17Upgrade linux-image-6.8.0-1050-gkeUpgrade linux-image-azureUpgrade linux-image-6.8.0-1050-gke-64kUpgrade linux-image-ibm-lts-24.04Upgrade linux-image-lowlatency-6.8Upgrade linux-image-6.8.0-1052-raspiUpgrade linux-image-6.8.0-1054-azure-fipsUpgrade linux-image-oem-22.04dUpgrade linux-image-6.17.0-1012-awsUpgrade linux-image-ibmUpgrade linux-image-virtual-6.8Upgrade linux-image-oracle-lts-24.04Upgrade linux-image-lowlatency-64kUpgrade linux-image-generic-6.8Upgrade linux-image-intel-iot-realtimeUpgrade linux-image-oem-24.04cUpgrade linux-image-oem-24.04bUpgrade linux-image-gcp-lts-24.04Upgrade linux-image-oem-22.04cUpgrade linux-image-lowlatency-64k-hwe-22.04Upgrade linux-image-nvidia-tegraUpgrade linux-image-6.8.0-1022-nvidia-tegra-rtUpgrade linux-image-realtime-hwe-22.04Upgrade linux-image-6.8.0-1059-azureUpgrade linux-image-6.8.0-1049-oracleUpgrade linux-image-6.8.0-1051-nvidia-64kUpgrade linux-image-virtualUpgrade linux-image-gcpUpgrade linux-image-6.17.0-1020-oemUpgrade linux-image-6.17.0-1010-realtimeUpgrade linux-image-xilinx-zynqmpUpgrade linux-image-generic-64k-hwe-22.04Upgrade linux-image-oracle-64kUpgrade linux-image-oem-24.04Upgrade linux-image-gkeop-6.8Upgrade linux-image-aws-lts-24.04Upgrade linux-image-6.17.0-1012-gcp-64kUpgrade linux-image-virtual-hwe-22.04Upgrade linux-image-gcp-fips-6.8Upgrade linux-image-gcp-64k-6.8Upgrade linux-image-oem-24.04aUpgrade linux-image-raspi-realtimeUpgrade linux-image-oem-24.04dUpgrade linux-image-lowlatency-64k-6.8Upgrade linux-image-intel-iotgUpgrade linux-image-generic-64kUpgrade linux-image-6.8.0-110-lowlatency-64kUpgrade linux-image-6.8.0-1051-nvidiaUpgrade linux-image-6.8.0-1051-ibmUpgrade linux-image-6.8.0-1054-gcp-fipsUpgrade linux-image-6.8.0-1054-gcpUpgrade linux-image-6.8.0-1037-gkeopUpgrade linux-image-nvidia-hwe-22.04Upgrade linux-image-gkeopUpgrade linux-image-nvidia-lowlatency-64k-6.8Upgrade linux-image-oracleUpgrade linux-image-realtime-6.17Upgrade linux-image-raspi-6.17Upgrade linux-image-nvidia-lowlatency-6.8Upgrade linux-image-nvidia-64kUpgrade linux-image-fips-6.8Upgrade linux-image-azure-fips-6.8Upgrade linux-image-aws-6.17Upgrade linux-image-6.8.0-110-generic-64kUpgrade linux-image-virtual-6.17Upgrade linux-image-6.17.0-1011-oracleUpgrade linux-image-oem-22.04bUpgrade linux-image-oem-22.04Upgrade linux-image-nvidiaUpgrade linux-image-gke-6.8Upgrade linux-image-generic-hwe-22.04Upgrade linux-image-gcp-6.8Upgrade linux-image-6.8.0-1054-gcp-64kUpgrade linux-image-6.17.0-1012-aws-64kUpgrade linux-image-xilinxUpgrade linux-image-generic-hwe-24.04Upgrade linux-image-nvidia-tegra-rt-6.8Upgrade linux-image-6.8.0-110-fipsUpgrade linux-image-virtual-hwe-24.04Upgrade linux-image-realtimeUpgrade linux-image-ibm-6.8Upgrade linux-image-gkeUpgrade linux-image-genericUpgrade linux-image-azure-6.8Upgrade linux-image-aws-64kUpgrade linux-image-6.8.0-1049-oracle-64k | Apr 17, 2026 | Jan 13, 2026 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | May 27, 2026 | Jan 13, 2026 |
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