CVE-2026-43324USB: dummy-hcd: Fix interrupt synchronization error
Updated under an hour ago ()
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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.
- CVSS
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Analyzed
- Record last updated
- Aug 5, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 04145a03db9d78469e0817ab3a767c76c0fb0947 before d847f375b1bcea713143bc02720d13d2d01b012a; from 04145a03db9d78469e0817ab3a767c76c0fb0947 before cbf7df5e5d27cd5bea92ee9a75a4b28dbcc718d4; 04145a03db9d78469e0817ab3a767c76c0fb0947 builds before 5aa776c8615bea3b1eaeec87b0788375800ead4f; 04145a03db9d78469e0817ab3a767c76c0fb0947 builds before 94d4fab1dd9e64f45449bcc7d6a5acf796b13015; from 04145a03db9d78469e0817ab3a767c76c0fb0947 before 5687a09776069bd915560021c9728ca528440128; 04145a03db9d78469e0817ab3a767c76c0fb0947 builds before 8bcd80219d8e10e660bf29b20e41bb8beb4e4cb7; 04145a03db9d78469e0817ab3a767c76c0fb0947 builds before 2ca9e46f8f1f5a297eb0ac83f79d35d5b3a02541 | CNA record |
linux linux_kernel linux:linux_kernel | from 5.14 before 5.15.203; from 5.16 before 6.1.168; from 6.2 before 6.6.134; from 6.7 before 6.12.81; from 6.13 before 6.18.22; from 6.19 before 6.19.12; 7.0; 7.0; and 5 more ranges | NVD |
References
- https://git.kernel.org/stable/c/d847f375b1bcea713143bc02720d13d2d01b012apatch
- https://git.kernel.org/stable/c/cbf7df5e5d27cd5bea92ee9a75a4b28dbcc718d4patch
- https://git.kernel.org/stable/c/5aa776c8615bea3b1eaeec87b0788375800ead4fpatch
- https://git.kernel.org/stable/c/94d4fab1dd9e64f45449bcc7d6a5acf796b13015patch
- https://git.kernel.org/stable/c/5687a09776069bd915560021c9728ca528440128patch
- https://git.kernel.org/stable/c/8bcd80219d8e10e660bf29b20e41bb8beb4e4cb7patch
- https://git.kernel.org/stable/c/2ca9e46f8f1f5a297eb0ac83f79d35d5b3a02541patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.