CVE-2026-72470 fs/ntfs3: resize log->one_page_buf when adopting on-disk page size
A buffer overflow in the Linux kernel NTFS3 driver allows attackers to cause memory corruption and potential code execution by mounting a specially crafted dirty NTFS volume.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72470?
CVE-2026-72470 is a high-severity memory corruption vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: resize log->one_page_buf when adopting on-disk page size
log_replay() allocates log->one_page_buf using the page size that was chosen from the host PAGE_SIZE:
log->one_page_buf = kmalloc(log->page_size, GFP_NOFS);
Later, when a restart area is found, the log page size recorded on disk is adopted:
t32 = le32_to_cpu(log->rst_info.r_page->sys_page_size); if (log->page_size != t32) { log->l_size = log->orig_file_size; log->page_size = norm_file_page(t32, &log->l_size, t32 == DefaultLogPageSize); }
If the on-disk page size is larger than the size used for the initial allocation, log->page_size grows but one_page_buf is left at its original, smaller size. A subsequent unaligned read_log_page() then reads log->page_size bytes into the undersized scratch buffer:
page_buf = page_off ? log->one_page_buf : *buffer; err = ntfs_read_run_nb_ra(ni->mi.sbi, &ni->file.run, page_vbo, page_buf, log->page_size, NULL, &log->read_ahead);
overflowing the allocation. This is reachable when mounting a dirty NTFS volume whose log was formatted with a page size larger than the buffer initially allocated on the mounting host (for example a 64K-log volume mounted on a host that allocated a 4K scratch buffer).
Grow one_page_buf when the adopted on-disk page size exceeds the size used for the initial allocation. On krealloc() failure the original buffer is left intact and freed by the existing error path.
Which versions are affected by CVE-2026-72470?
How do I fix CVE-2026-72470?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-72470 being exploited?
There is no known exploitation of CVE-2026-72470 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72470, DEBIAN-CVE-2026-72470, GHSA-mxhq-w28g-hr4q, UBUNTU-CVE-2026-72470.