HID: wacom: validate report length in wacom_intuos_pro2_bt_irq

Summary

In the Linux kernel, the following vulnerability has been resolved: HID: wacom: validate report length in wacom_intuos_pro2_bt_irq wacom_intuos_pro2_bt_irq() receives the wire report length in `len` but never consults it before parsing. After the report-id gate it unconditionally calls wacom_intuos_pro2_bt_pen() and then, selected by features.type, a fixed chain of sub-parsers, none of which receive `len`: wacom_intuos_pro2_bt_pen(wacom); if (type == INTUOSP2_BT || type == INTUOSP2S_BT) { wacom_intuos_pro2_bt_touch(wacom); wacom_intuos_pro2_bt_pad(wacom); wacom_intuos_pro2_bt_battery(wacom); } else { wacom_intuos_gen3_bt_pad(wacom); wacom_intuos_gen3_bt_battery(wacom); } Each sub-parser dereferences wacom->data at fixed offsets. The furthest byte touched on each branch is: INTUOSP2_BT / INTUOSP2S_BT: wacom_intuos_pro2_bt_pad() reads data[285] (the touchring byte), so the report must be at least 286 bytes; INTUOSHT3_BT ("gen3"): wacom_intuos_gen3_bt_battery() reads data[45], so the report must be at least 46 bytes. features.type is selected from the VID/PID id_table entry and wacom_setup_device_quirks() force-registers the pen/pad/touch inputs for that type independent of the report descriptor, so a malicious or malfunctioning paired/spoofed Bluetooth peripheral can advertise that VID/PID and send an undersized report that still satisfies the data[0] == 0x80/0x81 gate. The driver then reads past the received report and forwards the bytes to userspace via evdev (MSC_SERIAL / ABS_MISC / ABS_WHEEL on the pen and pad input nodes), an out-of-bounds read with a concrete userspace read-back channel, and a true out-of-bounds read on transports whose backing buffer is sized to the (small) report descriptor rather than a fixed-size staging buffer. This is the same class of bug commit 2f1763f62909 ("HID: wacom: fix out-of-bounds read in wacom_intuos_bt_irq") already hardened in the sibling wacom_intuos_bt_irq(), which guards each report id against its minimum length before parsing. Guard wacom_intuos_pro2_bt_irq() the same way: before parsing, reject reports shorter than the furthest offset the selected branch actually dereferences, warn, and bail out. Because the whole pen/touch/pad/ battery chain runs unconditionally per branch, a single up-front check against the maximum offset (286 bytes for INTUOSP2_BT/INTUOSP2S_BT, 46 bytes for the gen3 branch) bounds every sub-parser. Returning 0 on a short report also skips those calls for the same malformed report, which is the safe, conservative behavior.

Timeline

1. Sep 16, 2026, 10:33 AM UTCCVE published
2. Oct 19, 2026, 8:56 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 4922cd26f03c1c71bf7dd6cbdb638e7e36a4a50b · fixed in d2844f3fcd058113acbe0aa110ab13ef28b98d9f; From 4922cd26f03c1c71bf7dd6cbdb638e7e36a4a50b · fixed in 1bfc0547b81d5861443420d19b5ed2fd533cd17f; From 4922cd26f03c1c71bf7dd6cbdb638e7e36a4a50b · fixed in 84781a1f3c5dc6650480be9329e6e8528939eaa0; From 4922cd26f03c1c71bf7dd6cbdb638e7e36a4a50b · fixed in 96dd0af7597aba2d80cc97e2f66e8b72d30ba125; From 4922cd26f03c1c71bf7dd6cbdb638e7e36a4a50b · fixed in 114af803e409a68e52516810ecd24df4d8ce0c68; From 4922cd26f03c1c71bf7dd6cbdb638e7e36a4a50b · fixed in 74ec08f7b81c2726578039ca6dea0fec136c38ea; From 4922cd26f03c1c71bf7dd6cbdb638e7e36a4a50b · fixed in 0cdc6cb242dd8d2731956fdf3390de094482a4b2; From 4922cd26f03c1c71bf7dd6cbdb638e7e36a4a50b · fixed in a8e04f3f894ccb52cfcd7e60125a9f35da4a616d

• Linux Linux

  4.11

• KernelLinux

  From 4.11.0 · fixed in 5.10.270; From 5.11.0 · fixed in 5.15.221; From 5.16.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.51; From 6.19.0 · fixed in 7.2.5

References 8