CVE-2026-98201

Description

In the Linux kernel, the following vulnerability has been resolved: Input: zero ff_effect before compat copy in input_ff_effect_from_user In the compat path input_ff_effect_from_user() aliases the caller's native struct ff_effect with the smaller struct ff_effect_compat and copies only the compat sized prefix: compat_effect = (struct ff_effect_compat *)effect; if (copy_from_user(compat_effect, buffer, sizeof(struct ff_effect_compat))) The tail of the native structure is never written. Callers pass an uninitialized on-stack object, for example evdev_do_ioctl() for EVIOCSFF, so those bytes keep their previous stack contents. input_ff_upload() then stores the full native structure in ff->effects[id], from where a uinput based force feedback daemon can read it back via UI_BEGIN_FF_UPLOAD, disclosing kernel stack memory to userspace. Zero the effect before the compat copy.

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EPSS — Exploit Prediction

0.0018

Probability of exploitation

0.07%

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/0d05b43b55d4784a42ce8fb318175f8ad7d9af5a https://git.kernel.org/stable/c/6c26681c5668c973bd0e951407d670ac60d9cd66 https://git.kernel.org/stable/c/b878720e8bcaa4cf7163a5081f904dd6baf11b2c https://git.kernel.org/stable/c/c5e573bb095d502be7cbbaa99c26a20984111c6d https://git.kernel.org/stable/c/ec174c2ab1abb76b20fa167c6db848c3d97aa838 https://git.kernel.org/stable/c/ed0406e490f48ed180df140fe2a81be26bccb1a9 https://git.kernel.org/stable/c/ed0905fda39682d3da7937184397d3276abbffa8 https://git.kernel.org/stable/c/f84819ef8d66931ee3998fee3c4f03230f4cb6cc

Frequently Asked Questions

What is CVE-2026-98201? +

In the Linux kernel, the following vulnerability has been resolved: Input: zero ff_effect before compat copy in input_ff_effect_from_user In the compat path input_ff_effect_from_user() aliases the caller's native struct ff_effect with the smaller struct ff_effect_compat and copies only the compat sized prefix: compat_effect = (struct ff_effect_compat *)effect; if (copy_from_user(compat_effect, buffer, sizeof(struct ff_effect_compat))) The tail of the native structure is never written. Callers pass an uninitialized on-stack object, for example evdev_do_ioctl() for EVIOCSFF, so those bytes keep their previous stack contents. input_ff_upload() then stores the full native structure in ff->effects[id], from where a uinput based force feedback daemon can read it back via UI_BEGIN_FF_UPLOAD, disclosing kernel stack memory to userspace. Zero the effect before the compat copy.

How do I check if I'm vulnerable to CVE-2026-98201? +

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.