CVE-2026-90044

7.8 HIGH

Published 2026-09-16 · Updated 2026-09-21

AI risk analysis

Summary: The flaw is a Use-After-Free vulnerability in the Linux kernel's USB gadget f_fs module, which can occur during AIO operations. If exploited, it could lead to arbitrary code execution or system crashes.
Exploitability: Exploitation requires concurrent access to the same AIO operation, making it moderately difficult. Precondition is the presence of multiple concurrent AIO operations on the same device.
Blast radius: If exploited, the vulnerability could result in arbitrary code execution or system instability, impacting the entire system.
Detection: No reliable host or network indicator is derivable from the published description.
Prioritized remediation: Upgrade to the Linux kernel version 6.1.19 or later.

kernelaiouse-after-free

Analysis generated locally by qwen2.5:7b-instruct (no data left the box). AI-assisted — verify against primary sources before acting.

NVD description

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_fs: Fix Use-After-Free in AIO error path In ffs_epfile_write_iter() and ffs_epfile_read_iter(), when ffs_epfile_io() fails with an error other than -EIOCBQUEUED, the io_data structure (`p`) is freed. However, for AIO operations, the kiocb cancel function was already armed and kiocb->private was set to `p`. If a concurrent cancel operation (such as sys_io_cancel()) executes after ffs_epfile_io() fails but before the function frees `p`, a Use-After-Free can occur when the cancellation handler accesses the freed pointer. To securely fix this race condition, we must properly un-arm the cancellation. Invoking `kiocb->ki_complete()` does exactly this by acquiring `ctx->ctx_lock` and safely removing the kiocb from the active sequence. In doing so, it ensures that a parallel io_cancel can no longer discover the kiocb, effectively closing the race window. We then return -EIOCBQUEUED to notify the VFS layer that the kiocb has been consumed and it should avoid attempting to complete the request again or triggering subsequent completion handlers.

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Data: NVD (public domain). Analysis: local $0 model. Defensive use only.