Bug 2525401 (CVE-2026-80672)
| Summary: | CVE-2026-80672 kernel: ntfs: fix u16 truncation of restart-area length check | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | rhel-process-autobot, watson-tool-maintainers |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in the Linux kernel's NTFS filesystem driver. This vulnerability arises from an integer truncation error when validating the size of the $LogFile restart area and its log client record array. An attacker can exploit this by mounting a specially crafted NTFS image, leading to an out-of-bounds read. This could result in information disclosure or a denial of service.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
In the Linux kernel, the following vulnerability has been resolved: ntfs: fix u16 truncation of restart-area length check ntfs_check_restart_area() validates that the $LogFile restart area and its trailing log client record array fit within the system page size: u16 ra_ofs, ra_len, ca_ofs; ... ra_len = ca_ofs + le16_to_cpu(ra->log_clients) * sizeof(struct log_client_record); if (ra_ofs + ra_len > le32_to_cpu(rp->system_page_size) || ...) return false; ra_len is u16, but the right-hand side is computed in size_t (sizeof(struct log_client_record) == 160). Both ca_ofs and log_clients come straight from the on-disk restart area. With an on-disk log_clients of 410 the product 410 * 160 = 65600; adding ca_ofs and storing into the u16 ra_len truncates modulo 65536 (e.g. ca_ofs 64 gives ra_len 128), so the "fits in the page" check passes even though the client array described by log_clients extends far beyond the page. ntfs_check_log_client_array() then walks the array bounded only by the on-disk log_clients count: cr = ca + idx; if (cr->prev_client != LOGFILE_NO_CLIENT) ... For log_clients 410 it dereferences records up to ca + 409 * 160, ~64 KiB past the kvzalloc(system_page_size) restart-page buffer -- an out-of-bounds read of attacker-controlled extent, reachable when a crafted NTFS image is mounted (load_and_check_logfile() at mount time). This is the in-kernel analogue of CVE-2022-30789, fixed in the ntfs-3g userspace driver but never in this revived classic driver. Compute the restart-area length in a u32 so the existing bounds check rejects an over-large client array instead of being defeated by the truncation. Widen ra_ofs and ca_ofs to u32 as well: both are loaded from __le16 on-disk fields and every comparison already promotes to int/size_t, so this changes no result and keeps the declaration uniform.