CVE-2026-31624

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.

• linux linux kernel (>= 2.6.20.1 < 6.6.136) • linux linux kernel (>= 6.7 < 6.12.83) • linux linux kernel (>= 6.13 < 6.18.24) • linux linux kernel (>= 6.19 < 6.19.14) • linux linux kernel (>= 7.0 < 7.0.1) • linux linux kernel 2.6.20