CVE-2026-63903
Received Received - Intake

USB: serial: belkin_sa buffer overflow in interrupt handling

Publication date: 2026-07-19

Last updated on: 2026-07-19

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: USB: serial: belkin_sa: validate interrupt status length The Belkin interrupt callback treats interrupt data as a four-byte status report and reads LSR/MSR fields at offsets 2 and 3. The interrupt-in buffer length is derived from endpoint wMaxPacketSize, and short interrupt transfers may complete successfully with a smaller actual_length. Check the completed interrupt packet length before parsing status fields so short interrupt endpoints and short successful packets are ignored instead of causing out-of-bounds or stale status-byte reads. KASAN report as below: BUG: KASAN: slab-out-of-bounds in belkin_sa_read_int_callback() Read of size 1 Call trace: belkin_sa_read_int_callback() (drivers/usb/serial/belkin_sa.c:202) __usb_hcd_giveback_urb() (drivers/usb/core/hcd.c:1630) dummy_timer() (?:?)

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Meta Information

Published
2026-07-19
Last Modified
2026-07-19
Generated
2026-07-20
AI Q&A
2026-07-19
EPSS Evaluated
N/A
NVD
CVE-2026-63903
EUVD
EUVD-2026-45676

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
belkin belkin_sa *

Helpful Resources

Exploitability

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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves the Belkin USB serial driver. The interrupt callback function incorrectly assumes interrupt data is always four bytes long and reads status fields at fixed offsets. If a short interrupt transfer occurs, the function may read out-of-bounds memory or stale data, leading to a slab-out-of-bounds error detected by KASAN.

Detection Guidance

This vulnerability is specific to the Linux kernel's USB serial driver for Belkin devices. Detection requires checking kernel logs for KASAN slab-out-of-bounds errors related to belkin_sa_read_int_callback(). Monitor dmesg or system logs for errors like 'Read of size 1' in the USB serial subsystem.

Impact Analysis

This vulnerability could cause system instability or crashes due to memory corruption. An attacker with physical access to a vulnerable system might exploit it to trigger kernel errors, potentially leading to denial-of-service conditions or unauthorized memory access.

Compliance Impact

This vulnerability does not directly affect compliance with standards like GDPR or HIPAA. It is a low-level kernel issue in USB serial driver handling that could lead to memory corruption but does not involve data exposure or privacy violations.

Mitigation Strategies

Update the Linux kernel to a patched version that includes the fix for this vulnerability. If immediate patching is not possible, disable the belkin_sa module by blacklisting it or unloading the module to prevent exploitation.

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