Description
In the Linux kernel, the following vulnerability has been resolved: usbip: vudc: fix NULL deref in vep_dequeue() vep_alloc_request() wasn't initializing vrequest->udc, so cancellations on the FunctionFS AIO path were arriving in vep_dequeue without a valid UDC reference. Since vrequest->udc is never actually properly used anywhere, we opt to remove it, and update vep_dequeue to obtain a reference to the udc with ep_to_vudc(), consistent with the other vep_ ops. AFAICT this bug has existed for ~10 years. Seems that nobody has really stressed the FunctionFS AIO path on usbip's vudc. I tested this fix in a QEMU aarch64 guest driving FunctionFS endpoints via AIO. Before the fix, running `usbip attach` from the host would cause the guest to oops with the following backtrace: Call trace: vep_dequeue+0x1c/0xe4 (P) usb_ep_dequeue+0x14/0x20 ffs_aio_cancel+0x24/0x34 __arm64_sys_io_cancel+0xb0/0x124 do_el0_svc+0x68/0x100 el0_svc+0x18/0x5c el0t_64_sync_handler+0x98/0xdc el0t_64_sync+0x154/0x158
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
b6a0ca11186759ad7045d68a5447b1e89f658384 to < 9858c91d9ee6a13c45311569039413729fc9b757affectedb6a0ca11186759ad7045d68a5447b1e89f658384 to < 1226293ec9bed3d4cc5b05eeeb811d315ca51652affectedb6a0ca11186759ad7045d68a5447b1e89f658384 to < 3750f75f29f99c0223601e2ee73ad084adec47bdaffectedb6a0ca11186759ad7045d68a5447b1e89f658384 to < d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97affectedb6a0ca11186759ad7045d68a5447b1e89f658384 to < 0025276175fbbe0dcbf3f84d090b0adee769e9d9affectedb6a0ca11186759ad7045d68a5447b1e89f658384 to < 347b59e9f96719d89b6ef555d02a18ada1a5846faffectedb6a0ca11186759ad7045d68a5447b1e89f658384 to < 0443e4416aa1ee97748d1ed904eaf3352c60045eaffectedb6a0ca11186759ad7045d68a5447b1e89f658384 to < c5371e0b91b24159a3ebaa61e70b0980bcf03c0aaffected
Linux Linux
Default version status: affected
4.7affected0 to < 4.7unaffected5.10.261 to ≤ 5.10.*unaffected5.15.212 to ≤ 5.15.*unaffected6.1.178 to ≤ 6.1.*unaffected6.6.145 to ≤ 6.6.*unaffected6.12.96 to ≤ 6.12.*unaffected6.18.39 to ≤ 6.18.*unaffected7.1.4 to ≤ 7.1.*unaffected7.2 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/9858c91d9ee6a13c45311569039413729fc9b757 ↗
- https://git.kernel.org/stable/c/1226293ec9bed3d4cc5b05eeeb811d315ca51652 ↗
- https://git.kernel.org/stable/c/3750f75f29f99c0223601e2ee73ad084adec47bd ↗
- https://git.kernel.org/stable/c/d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97 ↗
- https://git.kernel.org/stable/c/0025276175fbbe0dcbf3f84d090b0adee769e9d9 ↗
- https://git.kernel.org/stable/c/347b59e9f96719d89b6ef555d02a18ada1a5846f ↗
- https://git.kernel.org/stable/c/0443e4416aa1ee97748d1ed904eaf3352c60045e ↗
- https://git.kernel.org/stable/c/c5371e0b91b24159a3ebaa61e70b0980bcf03c0a ↗