{"id":"CVE-2026-64331","title":"usbip: vudc: fix NULL deref in vep_dequeue()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nusbip: vudc: fix NULL deref in vep_dequeue()\n\nvep_alloc_request() wasn't initializing vrequest->udc, so cancellations\non the FunctionFS AIO path were arriving in vep_de…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= b6a0ca11186759ad7045d68a5447b1e89f658384 < 9858c91d9ee6a13c45311569039413729fc9b757","Linux >= b6a0ca11186759ad7045d68a5447b1e89f658384 < 1226293ec9bed3d4cc5b05eeeb811d315ca51652","Linux >= b6a0ca11186759ad7045d68a5447b1e89f658384 < 3750f75f29f99c0223601e2ee73ad084adec47bd","Linux >= b6a0ca11186759ad7045d68a5447b1e89f658384 < d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97","Linux >= b6a0ca11186759ad7045d68a5447b1e89f658384 < 0025276175fbbe0dcbf3f84d090b0adee769e9d9","Linux >= b6a0ca11186759ad7045d68a5447b1e89f658384 < 347b59e9f96719d89b6ef555d02a18ada1a5846f","Linux >= b6a0ca11186759ad7045d68a5447b1e89f658384 < 0443e4416aa1ee97748d1ed904eaf3352c60045e","Linux >= b6a0ca11186759ad7045d68a5447b1e89f658384 < c5371e0b91b24159a3ebaa61e70b0980bcf03c0a","Linux 4.7"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T16:35:21.455334Z"},"published":"2026-07-25","updated":"2026-11-06","sourceUpdated":"2026-11-06T16:44:45.966Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64331","references":[{"url":"https://git.kernel.org/stable/c/9858c91d9ee6a13c45311569039413729fc9b757"},{"url":"https://git.kernel.org/stable/c/1226293ec9bed3d4cc5b05eeeb811d315ca51652"},{"url":"https://git.kernel.org/stable/c/3750f75f29f99c0223601e2ee73ad084adec47bd"},{"url":"https://git.kernel.org/stable/c/d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97"},{"url":"https://git.kernel.org/stable/c/0025276175fbbe0dcbf3f84d090b0adee769e9d9"},{"url":"https://git.kernel.org/stable/c/347b59e9f96719d89b6ef555d02a18ada1a5846f"},{"url":"https://git.kernel.org/stable/c/0443e4416aa1ee97748d1ed904eaf3352c60045e"},{"url":"https://git.kernel.org/stable/c/c5371e0b91b24159a3ebaa61e70b0980bcf03c0a"}],"tags":["cve.org"],"epss":0.00123,"epssPercentile":0.02029,"ingestedAt":"2026-11-06T16:57:43.198Z","slug":"CVE-2026-64331","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nusbip: vudc: fix NULL deref in vep_dequeue()\n\nvep_alloc_request() wasn't initializing vrequest->udc, so cancellations\non the FunctionFS AIO path were arriving in vep_dequeue without a valid\nUDC reference.\n\nSince vrequest->udc is never actually properly used anywhere, we opt to\nremove it, and update vep_dequeue to obtain a reference to the udc with\nep_to_vudc(), consistent with the other vep_ ops.\n\nAFAICT this bug has existed for ~10 years. Seems that nobody has really\nstressed the FunctionFS AIO path on usbip's vudc.\n\nI tested this fix in a QEMU aarch64 guest driving FunctionFS endpoints\nvia AIO. Before the fix, running `usbip attach` from the host would\ncause the guest to oops with the following backtrace:\n\nCall trace:\n vep_dequeue+0x1c/0xe4 (P)\n usb_ep_dequeue+0x14/0x20\n ffs_aio_cancel+0x24/0x34\n __arm64_sys_io_cancel+0xb0/0x124\n do_el0_svc+0x68/0x100\n el0_svc+0x18/0x5c\n el0t_64_sync_handler+0x98/0xdc\n el0t_64_sync+0x154/0x158\n\n## Affected\n\n- `Linux >= b6a0ca11186759ad7045d68a5447b1e89f658384 < 9858c91d9ee6a13c45311569039413729fc9b757`\n- `Linux >= b6a0ca11186759ad7045d68a5447b1e89f658384 < 1226293ec9bed3d4cc5b05eeeb811d315ca51652`\n- `Linux >= b6a0ca11186759ad7045d68a5447b1e89f658384 < 3750f75f29f99c0223601e2ee73ad084adec47bd`\n- `Linux >= b6a0ca11186759ad7045d68a5447b1e89f658384 < d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97`\n- `Linux >= b6a0ca11186759ad7045d68a5447b1e89f658384 < 0025276175fbbe0dcbf3f84d090b0adee769e9d9`\n- `Linux >= b6a0ca11186759ad7045d68a5447b1e89f658384 < 347b59e9f96719d89b6ef555d02a18ada1a5846f`\n- `Linux >= b6a0ca11186759ad7045d68a5447b1e89f658384 < 0443e4416aa1ee97748d1ed904eaf3352c60045e`\n- `Linux >= b6a0ca11186759ad7045d68a5447b1e89f658384 < c5371e0b91b24159a3ebaa61e70b0980bcf03c0a`\n- `Linux 4.7`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}