In the Linux kernel, the following vulnerability has been resolved: usb: storage: sierra_ms: reject short SWoC info transfers sierra_get_swoc_info() requests sizeof(struct swoc_info) (60) bytes from the device via usb_control_msg(), but its callers only treat a negative return value as failure. A device that answers the vendor-specific GetSwocInfo request with a short IN transfer is therefore accepted, leaving the tail of the freshly allocated (kmalloc(), non-zeroing) swoc_info buffer uninitialized. truinst_show() subsequently prints swocInfo->rev, swocInfo->LinuxSKU and swocInfo->LinuxVer from that buffer into the world-readable (0444) "truinst" sysfs attribute. An emulated/malicious USB device (VID 0x1199, PID 0x0fff) can exploit this to disclose up to 5 bytes of stale kernel heap memory (kmalloc-64) to unprivileged userspace, once per sysfs read, indefinitely. On kernels built without init_on_alloc this leaks recently freed heap contents. Only accept the transfer when the full structure was received. sierra_ms_init() already retries failed queries, so well-behaved devices are unaffected.
History

Fri, 30 Oct 2026 13:00:00 +0000


Fri, 23 Oct 2026 18:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-200
CWE-254

Fri, 23 Oct 2026 12:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-908
References
Metrics threat_severity

None

cvssV3_1

{'score': 3.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'}

threat_severity

Low


Wed, 21 Oct 2026 13:15:00 +0000


Sun, 18 Oct 2026 20:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-200
CWE-254

Sun, 18 Oct 2026 16:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: usb: storage: sierra_ms: reject short SWoC info transfers sierra_get_swoc_info() requests sizeof(struct swoc_info) (60) bytes from the device via usb_control_msg(), but its callers only treat a negative return value as failure. A device that answers the vendor-specific GetSwocInfo request with a short IN transfer is therefore accepted, leaving the tail of the freshly allocated (kmalloc(), non-zeroing) swoc_info buffer uninitialized. truinst_show() subsequently prints swocInfo->rev, swocInfo->LinuxSKU and swocInfo->LinuxVer from that buffer into the world-readable (0444) "truinst" sysfs attribute. An emulated/malicious USB device (VID 0x1199, PID 0x0fff) can exploit this to disclose up to 5 bytes of stale kernel heap memory (kmalloc-64) to unprivileged userspace, once per sysfs read, indefinitely. On kernels built without init_on_alloc this leaks recently freed heap contents. Only accept the transfer when the full structure was received. sierra_ms_init() already retries failed queries, so well-behaved devices are unaffected.
Title usb: storage: sierra_ms: reject short SWoC info transfers
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2026-10-18T15:48:07.367Z

Updated: 2026-10-30T12:39:39.761Z

Reserved: 2026-09-25T10:25:14.369Z

Link: CVE-2026-98771

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-18T16:17:31.020

Modified: 2026-10-30T13:21:26.747

Link: CVE-2026-98771

cve-icon Redhat

Severity : Low

Publid Date: 2026-10-18T00:00:00Z

Links: CVE-2026-98771 - Bugzilla