CVEvulnerability
CVE-2026-90044
7.8 HIGH
Official page ↗
- Status
- Received
- Published
- 2026-09-16
- Last modified
- 2026-10-21
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
- 7.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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.
References
- https://git.kernel.org/stable/c/0a2f71ccf9c2053de725e9a7922d081f3f3a3804 git.kernel.org
- https://git.kernel.org/stable/c/153b5ecd29ed055562400bc17c91df3fd869b0ce git.kernel.org
- https://git.kernel.org/stable/c/4a2fb2d12b87b43724230abb52a1440617c7b6cc git.kernel.org
- https://git.kernel.org/stable/c/b5f0e80a03e87bd932487e03248eae3ba3ed7b45 git.kernel.org
- https://git.kernel.org/stable/c/e78dcb1f7ec271449c54984dc90c62a5ba272de7 git.kernel.org