CVE-2026-74683

Description

In the Linux kernel, the following vulnerability has been resolved: Input: evdev - sanitize event type index when fetching event masks The user-supplied event type index passed to EVIOCGMASK / EVIOCSMASK ioctls is used to index the static counts array in evdev_get_mask_cnt() and client evmasks array in evdev_get_mask(). While the event type is architecturally bounded by EV_CNT, speculative execution may mispredict bounds checks and perform out-of-bounds loads. Sanitize the event type index in evdev_get_mask_cnt() branchlessly using array_index_mask_nospec(). This clamps the index to 0 for safe array access and forces the returned count to 0 speculatively when the index is out of bounds. We do not need additional array_index_nospec() calls in evdev_get_mask() because evdev_get_mask_cnt() speculatively forces the count (and resulting xfer_size) to 0 for out-of-bounds types, preventing any speculative memory access to client evmasks array.

References

• https://git.kernel.org/stable/c/3abd29c61d2ef37c4102cf755b18be53bb9dbea6
• https://git.kernel.org/stable/c/4034ef247a9dde3f56660b01f0c3280dac6b1274
• https://git.kernel.org/stable/c/433913b4a92214d76e9f0c03ad9128fec943d5f8
• https://git.kernel.org/stable/c/5db341189bb7ff041d570dbe36ecca7e32913927
• https://git.kernel.org/stable/c/810e1883d4815f29c30d900ad7333d03cc2515d1