CVE-2026-90391

Description

In the Linux kernel, the following vulnerability has been resolved: lib/test_hmm: fail dmirror_fault() when the mirrored mm is gone dmirror_fault() is called from the dmirror_read() and dmirror_write() retry loops after dmirror_do_read() or dmirror_do_write() finds a missing device page table entry. If the mirrored mm has already exited, mmget_not_zero() fails. The current code returns 0 in that case, which tells the caller that faulting succeeded even though no page was faulted and no device page table entry was installed. The caller then retries the same address, hits -ENOENT again, and can loop forever without making progress. Return -EFAULT instead, so the ioctl fails when the mirrored mm is no longer faultable.

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EPSS — Exploit Prediction

0.0021

Probability of exploitation

0.11%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/2636569ea7c19d9a40db4a1e8d0a027bdacf1569 https://git.kernel.org/stable/c/50606ced303782f8715e2d0b98ca374ea498fa29 https://git.kernel.org/stable/c/541a67f21ab807c8dbc0ea88d5a2eb73b2618090 https://git.kernel.org/stable/c/6a8024511ddf4877435c34fb3d6028aa8e590649 https://git.kernel.org/stable/c/701347e31aa607f3782403151a3125729d685275 https://git.kernel.org/stable/c/a2074f86fc9653831e4fb7b711bb715db330f182 https://git.kernel.org/stable/c/af7a6d6ec36a16a583ba2e4e9984c3cf1fe34655 https://git.kernel.org/stable/c/d8e64ffab01e032ae29159d27230ace8cf8bdc80

Frequently Asked Questions

What is CVE-2026-90391? +

In the Linux kernel, the following vulnerability has been resolved: lib/test_hmm: fail dmirror_fault() when the mirrored mm is gone dmirror_fault() is called from the dmirror_read() and dmirror_write() retry loops after dmirror_do_read() or dmirror_do_write() finds a missing device page table entry. If the mirrored mm has already exited, mmget_not_zero() fails. The current code returns 0 in that case, which tells the caller that faulting succeeded even though no page was faulted and no device page table entry was installed. The caller then retries the same address, hits -ENOENT again, and can loop forever without making progress. Return -EFAULT instead, so the ioctl fails when the mirrored mm is no longer faultable.

How do I check if I'm vulnerable to CVE-2026-90391? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.