CVE-2026-64565Input: ims-pcu - fix heap-buffer-overflow in ims_pcu_process_data()

Official description

In the Linux kernel, the following vulnerability has been resolved: Input: ims-pcu - fix heap-buffer-overflow in ims_pcu_process_data() The `ims_pcu_process_data()` processes incoming URB data byte by byte. However, it fails to check if the `read_pos` index exceeds IMS_PCU_BUF_SIZE. If a malicious USB device sends a packet larger than IMS_PCU_BUF_SIZE, `read_pos` will increment indefinitely. Moreover, since `read_pos` is located immediately after `read_buf`, the attacker can overwrite `read_pos` itself to arbitrarily control the index. This manipulated `read_pos` is subsequently used in `ims_pcu_handle_response()` to copy data into `cmd_buf`, leading to a heap buffer overflow. Specifically, an attacker can overwrite the `cmd_done.wait.head` located at offset 136 relative to `cmd_buf` in the `ims_pcu_handle_response()`. Consequently, when the driver calls `complete(&pcu->cmd_done)`, it triggers a control flow hijack by using the manipulated pointer. Fix this by adding a bounds check for `read_pos` before writing to `read_buf`. If the packet is too long, discard it, log a warning, and reset the parser state. [dtor: factor out resetting packet state, reset checksum as well]

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/06cfff93fd40441292567b999091beab11c74504
• https://git.kernel.org/stable/c/992a7173364dcf63e30012af43da3c2f279839f9
• https://git.kernel.org/stable/c/3a801bc75ba1d121d0ed60e7234f93ba5651d87d
• https://git.kernel.org/stable/c/40bbbf2e91fd60715525bf0405c67876af817edf
• https://git.kernel.org/stable/c/ca9f8c09845fb8c51b6d447f6428eecd1b8b0a49
• https://git.kernel.org/stable/c/d03a740e087de7dcb2a26dc1123377bd3d1d84ca
• https://git.kernel.org/stable/c/875115b82c295277b81b6dfee7debc725f44e854