CVE-2026-90044

usb: gadget: f_fs: Fix Use-After-Free in AIO error path

HIGH
7.8
CVSS Score
Published: September 16, 2026 at 10:33 AM UTC
Updated: October 21, 2026 at 01:20 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.8
Exploit prediction
EPSS 0.2%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.0de2080d41b5d584205e408d72021f0f335a046fc
Vendor states this is fixed in 153b5ecd29ed055562400bc17c91df3fd869b0ce (fixed)
Vendor states this is fixed in 4a2fb2d12b87b43724230abb52a1440617c7b6cc (fixed)
Vendor states this is fixed in b5f0e80a03e87bd932487e03248eae3ba3ed7b45 (fixed)
Vendor states this is fixed in e78dcb1f7ec271449c54984dc90c62a5ba272de7 (fixed)
Vendor states this is fixed in 4.0 (unaffected)
Vendor states this is fixed in 6.12.111 (unaffected)
Vendor states this is fixed in 6.18.51 (unaffected)
Vendor states this is fixed in 6.6.160 (unaffected)
Vendor states this is fixed in 7.2.5 (unaffected)
Vendor states this is fixed in 7.3 (unaffected)
Vendor states this is fixed in 7.3-rc1 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

CVSS

7.8HIGHLinux
Vector?

Quick Info

StatusRECEIVED

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