Executive brief
A vulnerability in the Linux kernel's Digi Acceleport USB serial driver can lead to data corruption or system instability. This driver is used to manage specific USB-to-serial hardware adapters. If exploited, it could cause the device to malfunction or crash the system, potentially disrupting operations that rely on serial communication.
Technical details
A vulnerability in `digi_write_inb_command()` within `drivers/usb/serial/digi_acceleport.c` in the Linux kernel leads to write buffer corruption. The function fails to properly return an error upon a timeout, instead updating the transfer buffer and attempting to resubmit the USB Request Block (URB). Additionally, a broken jiffies comparison in commands without a specified timeout (like break control) causes immediate URB corruption, particularly on 32-bit systems shortly after boot. An attacker with physical access to the USB interface or local access to the serial device could trigger this corruption to cause a Denial of Service (DoS) or unpredictable system behavior. Patches have been released across multiple stable kernel branches to add the missing return on timeout and fix the jiffies comparison logic.
Affected products
- Linux Linux Kernel 2.6.12 to 6.9.x
Timeline
- 2026-06-23: patched: Initial fix authored by Johan Hovold
- 2026-07-25: advisory: CVE-2026-64333 published
References
- https://git.kernel.org/stable/c/1243f120790042c2ac92e84e797dacc75fff4366
- https://git.kernel.org/stable/c/24ca1fea8f2753bf33e1d458ec1ae5d9b7796a65
- https://git.kernel.org/stable/c/2f296974acc279f05f284441bfe3064074958d11
- https://git.kernel.org/stable/c/5d9dc88bdf8897788b0eed57113e9eca7fd42ea9
- https://git.kernel.org/stable/c/699dfb6917503b3cda4d5da6941cf79c3c1b4c8b
- https://git.kernel.org/stable/c/a274b3794fe1852c3d9fe6d900b94053c0b03410
- https://git.kernel.org/stable/c/a3a13fdc53103b07335918e2cdeb465038a71725