CVE-2026-68456 - Vulnerability Details

- usb: atm: ueagle-atm: wait for pre-firmware load in .disconnect()

Description

In the Linux kernel, the following vulnerability has been resolved:

usb: atm: ueagle-atm: wait for pre-firmware load in .disconnect()

ueagle-atm uses the asynchronous request_firmware_nowait() in .probe(),
but does not wait for its completion, not even in .disconnect(); so, if the
device is unplugged meanwhile, its teardown runs concurrently with that.

Even though this inconsistency is worth addressing on its own, it has also
triggered several bug reports in syzbot over the years (some auto-closed)
where the firmware sysfs fallback mechanism (CONFIG_FW_LOADER_USER_HELPER)
creates a firmware subdirectory in the device directory during its removal,
which might hit unexpected conditions in kernfs, apparently, depending at
which point the add and remove operations raced. (See links.)

The pattern is:

usb ?-?: Direct firmware load for ueagle-atm/eagle?.fw failed with error -2
usb ?-?: Falling back to sysfs fallback for: ueagle-atm/eagle?.fw
<ERROR>
Call trace:
...
kernfs_create_dir_ns
sysfs_create_dir_ns
create_dir
kobject_add_internal
kobject_add_varg
kobject_add
class_dir_create_and_add
get_device_parent
device_add
fw_load_sysfs_fallback
fw_load_from_user_helper
firmware_fallback_sysfs
_request_firmware
request_firmware_work_func
...

(Some variations are observed, after fw_load_sysfs_fallback(), e.g., [1].)

While the kernfs side is being looked at, the ueagle-atm side can be fixed
by waiting for the pre-firmware load in the .disconnect() handler.

This change has a similar approach to previous work by Andrey Tsygunka [2]
(wait_for_completion() in .disconnect()), but it is relatively different in
design/implementation; using the Originally-by tag for credit assignment.

This has been tested with:
- synthetic reproducer to check the error path;
- USB gadget (virtual device) to check the firmware upload path;
- QEMU device emulator to check the device ID re-enumeration path;
(The latter two were written by Claude; no other code/text in this commit.)

Links (year first reported):
2025 https://syzbot.org/bug?extid=ce1e5a1b4e086b43e56d
2025 https://syzbot.org/bug?extid=9af8471255ac36e34fd4
2024 https://syzbot.org/bug?extid=306212936b13e520679d
2023 https://syzkaller.appspot.com/bug?extid=457452d30bcdda75ead2
2022 https://syzbot.org/bug?extid=782984d6f1701b526edb
2021 https://syzbot.org/bug?id=f3f221579f4ef7e9691281f3c6f56c05f83e8490
2021 https://syzbot.org/bug?id=84d86f0d71394829df6fc53daf6642c045983881
2021 https://syzbot.org/bug?id=3302dc1c0e2b9c94f2e8edb404eabc9267bc6f90

[1] https://syzkaller.appspot.com/bug?extid=457452d30bcdda75ead2
[2] https://lore.kernel.org/lkml/20250410093146.3776801-2-aitsygunka@yandex.ru/

Published: 2026-08-15

Score: n/a

EPSS: n/a

KEV: No

Impact:

Action:

Analysis

Impact

The Linux kernel’s ueagle‑atm driver asynchronously requests a firmware file during device initialization but does not wait for the request to complete. If the USB device is unplugged while the firmware load is still in progress, the driver’s cleanup code may execute concurrently with the pending firmware load, causing the firmware subsystem to create a sysfs directory after the device has been removed. This race can trigger unexpected kernel state changes and has repeatedly caused kernel crashes, indicating a potential denial‑of‑service scenario.

Affected Systems

All Linux kernel installations that include the ueagle‑atm driver and use the asynchronous firmware request path, regardless of distribution. No specific kernel version was identified in the advisory, so any build lacking the patch may be vulnerable.

Risk and Exploitability

TheSS score is not listed and the EPSS data is unavailable, preventing a precise numerical severity assessment. However, the issue is linked to kernel panics observed by the syzkaller testing framework, suggesting a high impact if the race is exercised. Exploitation would require an attacker to cause a disconnect while the firmware load is pending, which can be achieved through physical or remote USB manipulation depending on the device exposure. The vulnerability is not currently in the CISA KEV catalog.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Linux

unaffected

Version	Status	Constraints
`b72458a80c75cab832248f536412f386e20a93a0`	affected	< d85f19aaef42a03e3e4765d659c761c8750a7f23
`b72458a80c75cab832248f536412f386e20a93a0`	affected	< 76861031b43a18065d13f9ffb8595d25c7576005
`b72458a80c75cab832248f536412f386e20a93a0`	affected	< bbfedc84714064ea4845e6b76f96316eb5bb65d8
`b72458a80c75cab832248f536412f386e20a93a0`	affected	< f2a6abc670104fc3e383ee3b1cf35c070485e3df
`b72458a80c75cab832248f536412f386e20a93a0`	affected	< c581e30ae5b332d8acef64475a211b3f82099941
`b72458a80c75cab832248f536412f386e20a93a0`	affected	< 509b51327320bdeaef1969248177a446ded073ab
`b72458a80c75cab832248f536412f386e20a93a0`	affected	< ddcdac47e1f2651c7be60e299f98faf981522797
`b72458a80c75cab832248f536412f386e20a93a0`	affected	< e2674dfbed8a30d57e2bc872c4bfa6c3eec918bf

Linux

affected

Version	Status	Constraints
`2.6.16`	affected	—
`0`	unaffected	< 2.6.16
`5.10.261`	unaffected	≤ 5.10.*
`5.15.212`	unaffected	≤ 5.15.*
`6.1.178`	unaffected	≤ 6.1.*
`6.6.145`	unaffected	≤ 6.6.*
`6.12.97`	unaffected	≤ 6.12.*
`6.18.40`	unaffected	≤ 6.18.*
`7.1.5`	unaffected	≤ 7.1.*
`7.2-rc3`	unaffected	≤ *

No data.

Vendor Product Confidence Versions

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`[b72458a80c75cab832248f536412f386e20a93a0,d85f19aaef42a03e3e4765d659c761c8750a7f23)`	affected	code_commit	—
`[b72458a80c75cab832248f536412f386e20a93a0,76861031b43a18065d13f9ffb8595d25c7576005)`	affected	code_commit	—
`[b72458a80c75cab832248f536412f386e20a93a0,bbfedc84714064ea4845e6b76f96316eb5bb65d8)`	affected	code_commit	—
`[b72458a80c75cab832248f536412f386e20a93a0,c581e30ae5b332d8acef64475a211b3f82099941)`	affected	code_commit	—
`[b72458a80c75cab832248f536412f386e20a93a0,f2a6abc670104fc3e383ee3b1cf35c070485e3df)`	affected	code_commit	—
`[b72458a80c75cab832248f536412f386e20a93a0,509b51327320bdeaef1969248177a446ded073ab)`	affected	code_commit	—
`[b72458a80c75cab832248f536412f386e20a93a0,ddcdac47e1f2651c7be60e299f98faf981522797)`	affected	code_commit	—
`[b72458a80c75cab832248f536412f386e20a93a0,e2674dfbed8a30d57e2bc872c4bfa6c3eec918bf)`	affected	code_commit	—

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`2.6.16`	affected	semver	—
`[0,2.6.16)`	unaffected	semver	—
`[5.10.261,5.10.*]`	unaffected	generic	—
`[5.15.212,5.15.*]`	unaffected	generic	—
`[6.1.178,6.1.*]`	unaffected	generic	—
`[6.6.145,6.6.*]`	unaffected	generic	—
`[6.12.97,6.12.*]`	unaffected	generic	—
`[6.18.40,6.18.*]`	unaffected	generic	—
`[7.1.5,7.1.*]`	unaffected	generic	—
`[7.2-rc3,*]`	unaffected	generic	—

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Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

Apply the latest Linux kernel release that contains the fix for ueagle‑atm firmware load race
If an immediate kernel upgrade is not possible, disable the CONFIG_FW_LOADER_USER_HELPER configuration option to stop sysfs fallback during firmware loads
Monitor system logs for “kernel panic” or “ueagle‑atm” related errors and address any reboots promptly

Generated by OpenCVE AI on August 15, 2026 at 07:25 UTC.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

No CVSS v4.0

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/stable/c/509b51327320bdeaef1969248177a446ded073ab
https://git.kernel.org/stable/c/76861031b43a18065d13f9ffb8595d25c7576005
https://git.kernel.org/stable/c/bbfedc84714064ea4845e6b76f96316eb5bb65d8
https://git.kernel.org/stable/c/c581e30ae5b332d8acef64475a211b3f82099941
https://git.kernel.org/stable/c/d85f19aaef42a03e3e4765d659c761c8750a7f23
https://git.kernel.org/stable/c/ddcdac47e1f2651c7be60e299f98faf981522797
https://git.kernel.org/stable/c/e2674dfbed8a30d57e2bc872c4bfa6c3eec918bf
https://git.kernel.org/stable/c/f2a6abc670104fc3e383ee3b1cf35c070485e3df

History

Sat, 15 Aug 2026 07:45:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-362

Sat, 15 Aug 2026 06:00:00 +0000

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: usb: atm: ueagle-atm: wait for pre-firmware load in .disconnect() ueagle-atm uses the asynchronous request_firmware_nowait() in .probe(), but does not wait for its completion, not even in .disconnect(); so, if the device is unplugged meanwhile, its teardown runs concurrently with that. Even though this inconsistency is worth addressing on its own, it has also triggered several bug reports in syzbot over the years (some auto-closed) where the firmware sysfs fallback mechanism (CONFIG_FW_LOADER_USER_HELPER) creates a firmware subdirectory in the device directory during its removal, which might hit unexpected conditions in kernfs, apparently, depending at which point the add and remove operations raced. (See links.) The pattern is: usb ?-?: Direct firmware load for ueagle-atm/eagle?.fw failed with error -2 usb ?-?: Falling back to sysfs fallback for: ueagle-atm/eagle?.fw <ERROR> Call trace: ... kernfs_create_dir_ns sysfs_create_dir_ns create_dir kobject_add_internal kobject_add_varg kobject_add class_dir_create_and_add get_device_parent device_add fw_load_sysfs_fallback fw_load_from_user_helper firmware_fallback_sysfs _request_firmware request_firmware_work_func ... (Some variations are observed, after fw_load_sysfs_fallback(), e.g., [1].) While the kernfs side is being looked at, the ueagle-atm side can be fixed by waiting for the pre-firmware load in the .disconnect() handler. This change has a similar approach to previous work by Andrey Tsygunka [2] (wait_for_completion() in .disconnect()), but it is relatively different in design/implementation; using the Originally-by tag for credit assignment. This has been tested with: - synthetic reproducer to check the error path; - USB gadget (virtual device) to check the firmware upload path; - QEMU device emulator to check the device ID re-enumeration path; (The latter two were written by Claude; no other code/text in this commit.) Links (year first reported): 2025 https://syzbot.org/bug?extid=ce1e5a1b4e086b43e56d 2025 https://syzbot.org/bug?extid=9af8471255ac36e34fd4 2024 https://syzbot.org/bug?extid=306212936b13e520679d 2023 https://syzkaller.appspot.com/bug?extid=457452d30bcdda75ead2 2022 https://syzbot.org/bug?extid=782984d6f1701b526edb 2021 https://syzbot.org/bug?id=f3f221579f4ef7e9691281f3c6f56c05f83e8490 2021 https://syzbot.org/bug?id=84d86f0d71394829df6fc53daf6642c045983881 2021 https://syzbot.org/bug?id=3302dc1c0e2b9c94f2e8edb404eabc9267bc6f90 [1] https://syzkaller.appspot.com/bug?extid=457452d30bcdda75ead2 [2] https://lore.kernel.org/lkml/20250410093146.3776801-2-aitsygunka@yandex.ru/
Title		usb: atm: ueagle-atm: wait for pre-firmware load in .disconnect()
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/509b51327320bdeaef1969248177a446ded073ab https://git.kernel.org/stable/c/76861031b43a18065d13f9ffb8595d25c7576005 https://git.kernel.org/stable/c/bbfedc84714064ea4845e6b76f96316eb5bb65d8 https://git.kernel.org/stable/c/c581e30ae5b332d8acef64475a211b3f82099941 https://git.kernel.org/stable/c/d85f19aaef42a03e3e4765d659c761c8750a7f23 https://git.kernel.org/stable/c/ddcdac47e1f2651c7be60e299f98faf981522797 https://git.kernel.org/stable/c/e2674dfbed8a30d57e2bc872c4bfa6c3eec918bf https://git.kernel.org/stable/c/f2a6abc670104fc3e383ee3b1cf35c070485e3df

Subscriptions

Linux Linux Kernel

MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2026-08-15T05:51:17.487Z

Updated: 2026-08-15T05:51:17.487Z

Reserved: 2026-07-30T09:28:09.395Z

Link: CVE-2026-68456

Vulnrichment

No data.

NVD

Status : Received

Published: 2026-08-15T06:17:32.713

Modified: 2026-08-15T06:17:32.713

Link: CVE-2026-68456

Redhat

No data.

OpenCVE Enrichment

Updated: 2026-08-15T08:15:04Z

Weaknesses

CWE-362
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Impact

Affected Systems

Risk and Exploitability

Tracking

Subscriptions

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