CVE-2026-31624

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: HID: core: clamp report_size in s32ton() to avoid undefined shift s32ton() shifts by n-1 where n is the field's report_size, a value that comes directly from a HID device. The HID parser bounds report_size only to <= 256, so a broken HID device can supply a report descriptor with a wide field that triggers shift exponents up to 256 on a 32-bit type when an output report is built via hid_output_field() or hid_set_field(). Commit ec61b41918587 ("HID: core: fix shift-out-of-bounds in hid_report_raw_event") added the same n > 32 clamp to the function snto32(), but s32ton() was never given the same fix as I guess syzbot hadn't figured out how to fuzz a device the same way. Fix this up by just clamping the max value of n, just like snto32() does.

CVSS Score

Affected Products

References

• https://git.kernel.org/stable/c/58386f00af710922cafb0fb69211497beddfaa95Patch
• https://git.kernel.org/stable/c/69c02ffde6ed4d535fa4e693a9e572729cad3d0dPatch
• https://git.kernel.org/stable/c/8a8333237f1f5caab8d4c3d2c2e7578c4263a97fPatch
• https://git.kernel.org/stable/c/932ae5309e53561197aa7d1606c7cf63af10e24fPatch
• https://git.kernel.org/stable/c/97014719bb8fccb1ffcbbc299e84b1f11b114195Patch
• https://git.kernel.org/stable/c/ea363a34086ddb4231adc581a7f36c39ec154bfcPatch