CVE-2026-64289 (GCVE-0-2026-64289)
Vulnerability from cvelistv5 – Published: 2026-07-25 08:49 – Updated: 2026-08-17 04:52
VLAI
EPSS
VEX
Title
iommufd: Set upper bounds on cache invalidation entry_num and entry_len
Summary
In the Linux kernel, the following vulnerability has been resolved:
iommufd: Set upper bounds on cache invalidation entry_num and entry_len
iommufd_hwpt_invalidate() takes a user-controlled entry_num and entry_len,
each bounded only by U32_MAX. An entry_len beyond the kernel's struct size
makes the copy helper verify the extra bytes are zero, scanning that excess
in one uninterruptible pass; a multi-gigabyte value over zeroed user memory
trips the soft-lockup watchdog.
A large entry_num is the other half, driving the backend invalidation loop
with no reschedule. The VT-d nested handler, for one, copies each entry and
flushes caches per iteration, pinning the CPU on a non-preemptible kernel.
Cap both in the ioctl. entry_len is held under PAGE_SIZE, above any request
struct, and entry_num under 1 << 19, the order of a hardware invalidation
queue and well beyond any real batch, bounding the per-call loop length.
Severity
5.5 (Medium)
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
8c6eabae3807e048b9f17733af5e20500fbf858c , < d2bd041e0efaf7d81789779b135279d18b33d6d5
(git)
Affected: 8c6eabae3807e048b9f17733af5e20500fbf858c , < 32ca4aed2a66205b072fcfecabe220289a8149ff (git) Affected: 8c6eabae3807e048b9f17733af5e20500fbf858c , < 2c6381d90898089287e0a358f06f89f6b4b389f2 (git) Affected: 8c6eabae3807e048b9f17733af5e20500fbf858c , < 4d70986002f2f3eaaed89124fb2522bded38b016 (git) |
guessed | |
| Linux | Linux |
Affected:
6.8
Unaffected: 0 , < 6.8 (semver) Unaffected: 6.12.96 , ≤ 6.12.* (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.4 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix) |
guessed |
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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