In the Linux kernel, the following vulnerability has been resolved:

wifi: ath12k: fix out-of-bound access of qmi_invoke_handler()

Currently, there is no terminator entry for ath12k_qmi_msg_handlers hence facing below KASAN warning,

================================================================== BUG: KASAN: global-out-of-bounds in qmi_invoke_handler+0xa4/0x148 Read of size 8 at addr ffffffd00a6428d8 by task kworker/u8:2/1273

CPU: 0 PID: 1273 Comm: kworker/u8:2 Not tainted 5.4.213 #0 Workqueue: qmi_msg_handler qmi_data_ready_work Call trace: dump_backtrace+0x0/0x20c show_stack+0x14/0x1c dump_stack+0xe0/0x138 print_address_description.isra.5+0x30/0x330 __kasan_report+0x16c/0x1bc kasan_report+0xc/0x14 __asan_load8+0xa8/0xb0 qmi_invoke_handler+0xa4/0x148 qmi_handle_message+0x18c/0x1bc qmi_data_ready_work+0x4ec/0x528 process_one_work+0x2c0/0x440 worker_thread+0x324/0x4b8 kthread+0x210/0x228 ret_from_fork+0x10/0x18

The address belongs to the variable: ath12k_mac_mon_status_filter_default+0x4bd8/0xfffffffffffe2300 [ath12k] […]

Add a dummy terminator entry at the end to assist the qmi_invoke_handler() in traversing up to the terminator entry without accessing an out-of-boundary index.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.0.1-00029-QCAHKSWPL_SILICONZ-1

Weakness

The product reads data past the end, or before the beginning, of the intended buffer.

Affected Software

Potential Mitigations

• Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
• When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
• Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
• To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/540.html

References

• https://git.kernel.org/stable/c/95575de7dede7b1ed3b9718dab9dda97914ea775
• https://git.kernel.org/stable/c/a1abdb63628b04855a929850772de97435ed1555
• https://git.kernel.org/stable/c/b48d40f5840c505b7af700594aa8379eec28e925
• https://git.kernel.org/stable/c/e1bdff48a1bb4a4ac660c19c55a820968c48b3f2
• https://git.kernel.org/stable/c/95575de7dede7b1ed3b9718dab9dda97914ea775
• https://git.kernel.org/stable/c/a1abdb63628b04855a929850772de97435ed1555
• https://git.kernel.org/stable/c/b48d40f5840c505b7af700594aa8379eec28e925
• https://git.kernel.org/stable/c/e1bdff48a1bb4a4ac660c19c55a820968c48b3f2