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CVE PROGRAM SOURCE RECORDUnscored

CVE-2026-64331

usbip: vudc: fix NULL deref in vep_dequeue()

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 < 9858c91d9ee6a13c45311569039413729fc9b757affected
  • b6a0ca11186759ad7045d68a5447b1e89f658384 to < 1226293ec9bed3d4cc5b05eeeb811d315ca51652affected
  • b6a0ca11186759ad7045d68a5447b1e89f658384 to < 3750f75f29f99c0223601e2ee73ad084adec47bdaffected
  • b6a0ca11186759ad7045d68a5447b1e89f658384 to < d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97affected
  • b6a0ca11186759ad7045d68a5447b1e89f658384 to < 0025276175fbbe0dcbf3f84d090b0adee769e9d9affected
  • b6a0ca11186759ad7045d68a5447b1e89f658384 to < 347b59e9f96719d89b6ef555d02a18ada1a5846faffected
  • b6a0ca11186759ad7045d68a5447b1e89f658384 to < 0443e4416aa1ee97748d1ed904eaf3352c60045eaffected
  • b6a0ca11186759ad7045d68a5447b1e89f658384 to < c5371e0b91b24159a3ebaa61e70b0980bcf03c0aaffected

Linux Linux

Default version status: affected

  • 4.7affected
  • 0 to < 4.7unaffected
  • 5.10.261 to ≤ 5.10.*unaffected
  • 5.15.212 to ≤ 5.15.*unaffected
  • 6.1.178 to ≤ 6.1.*unaffected
  • 6.6.145 to ≤ 6.6.*unaffected
  • 6.12.96 to ≤ 6.12.*unaffected
  • 6.18.39 to ≤ 6.18.*unaffected
  • 7.1.4 to ≤ 7.1.*unaffected
  • 7.2 to ≤ *unaffected

References