CVE-2026-43324USB: dummy-hcd: Fix interrupt synchronization error
- 7.8HighCVSS base score
- 0.13%Exploitation in 30 daysEPSS · top 97% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: USB: dummy-hcd: Fix interrupt synchronization error This fixes an error in synchronization in the dummy-hcd driver. The error has a somewhat involved history. The synchronization mechanism was introduced by commit 7dbd8f4cabd9 ("USB: dummy-hcd: Fix erroneous synchronization change"), which added an emulated "interrupts enabled" flag together with code emulating synchronize_irq() (it waits until all current handler callbacks have returned). But the emulated interrupt-disable occurred too late, after the driver containing the handler callback routines had been told that it was unbound and no more callbacks would occur. Commit 4a5d797a9f9c ("usb: gadget: dummy_hcd: fix gpf in gadget_setup") tried to fix this by moving the synchronize_irq() emulation code from dummy_stop() to dummy_pullup(), which runs before the unbind callback. There still were races, though, because the emulated interrupt-disable still occurred too late. It couldn't be moved to dummy_pullup(), because that routine can be called for reasons other than an impending unbind. Therefore commits 7dc0c55e9f30 ("USB: UDC core: Add udc_async_callbacks gadget op") and 04145a03db9d ("USB: UDC: Implement udc_async_callbacks in dummy-hcd") added an API allowing the UDC core to tell dummy-hcd exactly when emulated interrupts and their callbacks should be disabled. That brings us to the current state of things, which is still wrong because the emulated synchronize_irq() occurs before the emulated interrupt-disable! That's no good, beause it means that more emulated interrupts can occur after the synchronize_irq() emulation has run, leading to the possibility that a callback handler may be running when the gadget driver is unbound. To fix this, we have to move the synchronize_irq() emulation code yet again, to the dummy_udc_async_callbacks() routine, which takes care of enabling and disabling emulated interrupt requests. The synchronization will now run immediately after emulated interrupts are disabled, which is where it belongs.
Timeline
ID reserved
By Linux
- 7 days later
· 7 days later
Published
- 3 months later
· 3 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.13% · top 97% of all CVEs (14 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected 04145a03db9d78469e0817ab3a767c76c0fb0947 – < d847f375b1bcea713143bc02720d13d2d01b012a
- affected 04145a03db9d78469e0817ab3a767c76c0fb0947 – < cbf7df5e5d27cd5bea92ee9a75a4b28dbcc718d4
- affected 04145a03db9d78469e0817ab3a767c76c0fb0947 – < 5aa776c8615bea3b1eaeec87b0788375800ead4f
- affected 04145a03db9d78469e0817ab3a767c76c0fb0947 – < 94d4fab1dd9e64f45449bcc7d6a5acf796b13015
- affected 04145a03db9d78469e0817ab3a767c76c0fb0947 – < 5687a09776069bd915560021c9728ca528440128
- affected 04145a03db9d78469e0817ab3a767c76c0fb0947 – < 8bcd80219d8e10e660bf29b20e41bb8beb4e4cb7
- affected 04145a03db9d78469e0817ab3a767c76c0fb0947 – < 2ca9e46f8f1f5a297eb0ac83f79d35d5b3a02541
- affected 5.14
- unaffected < 5.14
- unaffected 5.15.203 – ≤ 5.15.*
- unaffected 6.1.168 – ≤ 6.1.*
- unaffected 6.6.134 – ≤ 6.6.*
- unaffected 6.12.81 – ≤ 6.12.*
- unaffected 6.18.22 – ≤ 6.18.*
- unaffected 6.19.12 – ≤ 6.19.*
- unaffected 7.0 – ≤ *
References
References7
- https://git.kernel.org/stable/c/d847f375b1bcea713143bc02720d13d2d01b012a (opens in a new tab)
- https://git.kernel.org/stable/c/cbf7df5e5d27cd5bea92ee9a75a4b28dbcc718d4 (opens in a new tab)
- https://git.kernel.org/stable/c/5aa776c8615bea3b1eaeec87b0788375800ead4f (opens in a new tab)
- https://git.kernel.org/stable/c/94d4fab1dd9e64f45449bcc7d6a5acf796b13015 (opens in a new tab)
- https://git.kernel.org/stable/c/5687a09776069bd915560021c9728ca528440128 (opens in a new tab)
- https://git.kernel.org/stable/c/8bcd80219d8e10e660bf29b20e41bb8beb4e4cb7 (opens in a new tab)
- https://git.kernel.org/stable/c/2ca9e46f8f1f5a297eb0ac83f79d35d5b3a02541 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-28608 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-43324)Record last updated .