Advisory [CVE-2026-64331] fix NULL deref in vep_dequeue
This security Red Hat Linux advisory covers CVE-2026-64331.
Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.
VulniPulse record published Record updated
Android app · Google Play
Monitor future Red Hat Linux CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 32 official vendor sources and 160+ reviewed platform categories.
Summary
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.
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 A flaw was found in the Linux kernel's usbip virtual USB device controller (vudc).
This vulnerability, a NULL pointer dereference, occurs when vep_alloc_request() fails to initialize a vrequest's udc field, causing asynchronous input/output (AIO) cancellations on the FunctionFS path to arrive without a valid UDC reference.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 13 days ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 13 days ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 13 days ago·verify at source
Discussion(0)
No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.
Sign in to join the discussion.