Affected: Alpaquita:23: linux-lts, Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

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]

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]

Security update for the Linux Kernel

Security update for the Linux Kernel

Affected: Ubuntu:Pro:14.04:LTS: linux, Ubuntu:Pro:14.04:LTS: linux-aws, Ubuntu:Pro:14.04:LTS: linux-azure, Ubuntu:Pro:14.04:LTS: linux-lts-xenial, Ubuntu:Pro:16.04:LTS: linux, Ubuntu:Pro:16.04:LTS: linux-aws, Ubuntu:Pro:16.04:LTS: linux-aws-hwe, Ubuntu:Pro:16.04:LTS: linux-azure, Ubuntu:Pro:16.04:LTS: linux-gcp, Ubuntu:Pro:16.04:LTS: linux-hwe and 246 more

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]

Ein Angreifer kann mehrere Schwachstellen in Linux Kernel ausnutzen, um vertrauliche Informationen offenzulegen, Daten zu manipulieren, einen Denial-of-Service-Zustand zu verursachen oder seine Rechte zu erweitern.