CVE-2023-52901

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

usb: xhci: Check endpoint is valid before dereferencing it

When the host controller is not responding, all URBs queued to all endpoints need to be killed. This can cause a kernel panic if we dereference an invalid endpoint.

Fix this by using xhci_get_virt_ep() helper to find the endpoint and checking if the endpoint is valid before dereferencing it.

[233311.853271] xhci-hcd xhci-hcd.1.auto: xHCI host controller not responding, assume dead [233311.853393] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000e8

[233311.853964] pc : xhci_hc_died+0x10c/0x270 [233311.853971] lr : xhci_hc_died+0x1ac/0x270

[233311.854077] Call trace: [233311.854085] xhci_hc_died+0x10c/0x270 [233311.854093] xhci_stop_endpoint_command_watchdog+0x100/0x1a4 [233311.854105] call_timer_fn+0x50/0x2d4 [233311.854112] expire_timers+0xac/0x2e4 [233311.854118] run_timer_softirq+0x300/0xabc [233311.854127] __do_softirq+0x148/0x528 [233311.854135] irq_exit+0x194/0x1a8 [233311.854143] __handle_domain_irq+0x164/0x1d0 [233311.854149] gic_handle_irq.22273+0x10c/0x188 [233311.854156] el1_irq+0xfc/0x1a8 [233311.854175] lpm_cpuidle_enter+0x25c/0x418 [msm_pm] [233311.854185] cpuidle_enter_state+0x1f0/0x764 [233311.854194] do_idle+0x594/0x6ac [233311.854201] cpu_startup_entry+0x7c/0x80 [233311.854209] secondary_start_kernel+0x170/0x198

Weakness

A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/08864dc14a6803f0377ca77b9740b26db30c020f
• https://git.kernel.org/stable/c/2d2820d5f375563690c96e60676855205abfb7f5
• https://git.kernel.org/stable/c/375be2dd61a072f7b1cac9b17eea59e07b58db3a
• https://git.kernel.org/stable/c/66fc1600855c05c4ba4e997184c91cf298e0405c
• https://git.kernel.org/stable/c/9891e5c73cab3fd9ed532dc50e9799e55e974766
• https://git.kernel.org/stable/c/e8fb5bc76eb86437ab87002d4a36d6da02165654
• https://git.kernel.org/stable/c/f39c813af0b64f44af94e435c07bfa1ddc2575f5