{"id":"CVE-2026-98771","title":"usb: storage: sierra_ms: reject short SWoC info transfers","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: storage: sierra_ms: reject short SWoC info transfers\n\nsierra_get_swoc_info() requests sizeof(struct swoc_info) (60) bytes\nfrom the device via usb_control_msg(), bu…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 32fe5e393455d87db4988af03915634304870fb4 < c85e8331d298b8f1dee8fe63718e76435cec7133","Linux >= 32fe5e393455d87db4988af03915634304870fb4 < e2d62928f2666a2964a23b1d39e6e762f0628d7b","Linux >= 32fe5e393455d87db4988af03915634304870fb4 < db9d3be156baca6ef80ae5d93acfeb85c61a74dd","Linux >= 32fe5e393455d87db4988af03915634304870fb4 < 8a0200d14acd9db388b85cd016e68a4e60d900ec","Linux 2.6.27"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:48:07.367Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98771","references":[{"url":"https://git.kernel.org/stable/c/c85e8331d298b8f1dee8fe63718e76435cec7133"},{"url":"https://git.kernel.org/stable/c/e2d62928f2666a2964a23b1d39e6e762f0628d7b"},{"url":"https://git.kernel.org/stable/c/db9d3be156baca6ef80ae5d93acfeb85c61a74dd"},{"url":"https://git.kernel.org/stable/c/8a0200d14acd9db388b85cd016e68a4e60d900ec"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T16:47:32.492Z","slug":"CVE-2026-98771","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nusb: storage: sierra_ms: reject short SWoC info transfers\n\nsierra_get_swoc_info() requests sizeof(struct swoc_info) (60) bytes\nfrom the device via usb_control_msg(), but its callers only treat a\nnegative return value as failure. A device that answers the\nvendor-specific GetSwocInfo request with a short IN transfer is\ntherefore accepted, leaving the tail of the freshly allocated\n(kmalloc(), non-zeroing) swoc_info buffer uninitialized.\n\ntruinst_show() subsequently prints swocInfo->rev, swocInfo->LinuxSKU\nand swocInfo->LinuxVer from that buffer into the world-readable\n(0444) \"truinst\" sysfs attribute. An emulated/malicious USB device\n(VID 0x1199, PID 0x0fff) can exploit this to disclose up to 5 bytes\nof stale kernel heap memory (kmalloc-64) to unprivileged userspace,\nonce per sysfs read, indefinitely. On kernels built without\ninit_on_alloc this leaks recently freed heap contents.\n\nOnly accept the transfer when the full structure was received.\nsierra_ms_init() already retries failed queries, so well-behaved\ndevices are unaffected.\n\n## Affected\n\n- `Linux >= 32fe5e393455d87db4988af03915634304870fb4 < c85e8331d298b8f1dee8fe63718e76435cec7133`\n- `Linux >= 32fe5e393455d87db4988af03915634304870fb4 < e2d62928f2666a2964a23b1d39e6e762f0628d7b`\n- `Linux >= 32fe5e393455d87db4988af03915634304870fb4 < db9d3be156baca6ef80ae5d93acfeb85c61a74dd`\n- `Linux >= 32fe5e393455d87db4988af03915634304870fb4 < 8a0200d14acd9db388b85cd016e68a4e60d900ec`\n- `Linux 2.6.27`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}