This page tracks the Ubuntu fix status. The vulnerability itself is described on the main CVE page.
View CVE-2026-64431 →
UBUNTU-CVE-2026-64431
In the Linux kernel, the following vulnerability has been resolved: ntfs: avoid calling post_write_mst_fixup() for invalid index_block ntfs_icx_ib_syn...
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved: ntfs: avoid calling post_write_mst_fixup() for invalid index_block ntfs_icx_ib_sync_write() calls post_write_mst_fixup() when ntfs_ib_write() returns an error, intending to restore the buffer after a failed write. However, ntfs_ib_write() returns an error immediately if pre_write_mst_fixup() validation fails. The caller, ntfs_icx_ib_sync_write(), interprets any error as a write failure requiring rollback. It does not differentiate between I/O errors and validation failures, and calls post_write_mst_fixup() anyway. Since post_write_mst_fixup() assumes that the index_block contents is correct, it doesn't perform the boundary checks, which results in out-of-bounds memory access. An attacker can craft a malicious NTFS image with: - large index_block.usa_ofs offset, pointing outside the ntfs_record - index_block.usa_count = 0, causing integer underflow - or index_block.usa_count larger than actual number of sectors in the ntfs_record, causing out-of-bounds access KASAN reports describing the memory corruption: ================================================================== BUG: KASAN: slab-out-of-bounds in post_write_mst_fixup+0x19c/0x1d0 Read of size 2 at addr ffff8881586c9018 by task p/9428 Call Trace: dump_stack_lvl+0x100/0x190 print_report+0x139/0x4ad ? post_write_mst_fixup+0x19c/0x1d0 ? __virt_addr_valid+0x262/0x500 ? post_write_mst_fixup+0x19c/0x1d0 kasan_report+0xe…
Source: OSV.dev (Open Source Vulnerabilities) OSV
Affected packages
Ubuntu:16.04:LTS
linux-hwe-edge
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-aws-5.0
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-aws-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-azure
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-azure-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-azure-edge
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-gcp
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-gcp-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-gke-4.15
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-gke-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-gkeop-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-hwe
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-hwe-edge
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-oem
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-oracle-5.0
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-oracle-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-aws-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-aws-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-aws-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-azure-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-azure-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-azure-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-azure-fde
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-gcp-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-gcp-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-gcp-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-gke
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-gke-5.15
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-gkeop
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-gkeop-5.15
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-hwe-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-hwe-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-hwe-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-intel-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oem-5.10
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oem-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oem-5.14
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oem-5.6
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oracle-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oracle-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oracle-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-raspi2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-riscv
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-riscv-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-riscv-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-allwinner-5.19
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-aws-5.19
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-aws-6.2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-aws-6.5
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-azure-5.19
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-azure-6.2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-azure-6.5
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-azure-fde-5.19
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-azure-fde-6.2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-gcp-5.19
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-gcp-6.2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-gcp-6.5
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-hwe-5.19
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-hwe-6.2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-hwe-6.5
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-intel-iot-realtime
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-lowlatency-hwe-5.19
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-lowlatency-hwe-6.2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-lowlatency-hwe-6.5
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-nvidia-6.2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-nvidia-6.5
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-oem-5.17
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-oem-6.0
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-oem-6.1
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-oem-6.5
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-oracle-6.5
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-realtime
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-riscv
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-riscv-5.19
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-riscv-6.5
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-starfive-5.19
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-starfive-6.2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-starfive-6.5
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-aws-6.14
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-aws-6.17
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-azure-6.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-azure-6.14
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-azure-fde-6.14
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-azure-nvidia-6.14
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-gcp-6.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-gcp-6.14
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-hwe-6.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-hwe-6.14
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-lowlatency-hwe-6.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-nvidia-6.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-oem-6.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-oem-6.14
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-oem-6.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-oracle-6.14
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-raspi-realtime
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-realtime
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-riscv
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-riscv-6.14
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-riscv-6.17
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:Realtime:24.04:LTS
linux-realtime-6.14
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
References
- report ubuntu.com
- report cve.org
- report git.kernel.org
- report git.kernel.org
- report git.kernel.org