{"cve":"CVE-2025-68331","nvd":{"published":"2025-12-22T17:16:00.800","modified":"2026-10-19T21:10:00.160","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: uas: fix urb unmapping issue when the uas device is remove during ongoing data transfer\n\nWhen a UAS device is unplugged during data transfer, there is\na probability of a system panic occurring. The root cause is\nan access to an invalid memory address during URB callback handling.\nSpecifically, this happens when the dma_direct_unmap_sg() function\nis called within the usb_hcd_unmap_urb_for_dma() interface, but the\nsg->dma_address field is 0 and the sg data structure has already been\nfreed.\n\nThe SCSI driver sends transfer commands by invoking uas_queuecommand_lck()\nin uas.c, using the uas_submit_urbs() function to submit requests to USB.\nWithin the uas_submit_urbs() implementation, three URBs (sense_urb,\ndata_urb, and cmd_urb) are sequentially submitted. Device removal may\noccur at any point during uas_submit_urbs execution, which may result\nin URB submission failure. However, some URBs might have been successfully\nsubmitted before the failure, and uas_submit_urbs will return the -ENODEV\nerror code in this case. The current error handling directly calls\nscsi_done(). In the SCSI driver, this eventually triggers scsi_complete()\nto invoke scsi_end_request() for releasing the sgtable. The successfully\nsubmitted URBs, when being unlinked to giveback, call\nusb_hcd_unmap_urb_for_dma() in hcd.c, leading to exceptions during sg\nunmapping operations since the sg data structure has already been freed.\n\nThis patch modifies the error condition check in the uas_submit_urbs()\nfunction. When a UAS device is removed but one or more URBs have already\nbeen successfully submitted to USB, it avoids immediately invoking\nscsi_done() and save the cmnd to devinfo->cmnd array. If the successfully\nsubmitted URBs is completed before devinfo->resetting being set, then\nthe scsi_done() function will be called within uas_try_complete() after\nall pending URB operations are finalized. Otherwise, the scsi_done()\nfunction will be called within uas_zap_pending(), which is executed after\nusb_kill_anchored_urbs().\n\nThe error handling only takes effect when uas_queuecommand_lck() calls\nuas_submit_urbs() and returns the error value -ENODEV . In this case,\nthe device is disconnected, and the flow proceeds to uas_disconnect(),\nwhere uas_zap_pending() is invoked to call uas_try_complete().","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/26d56a9fcb2014b99e654127960aa0a48a391e3c","https://git.kernel.org/stable/c/2b90a8131c83f6f2be69397d2b7d14d217d95d2f","https://git.kernel.org/stable/c/426edbfc88b22601ea34a441a469092e7b301c52","https://git.kernel.org/stable/c/6289fc489e94c9beb6be2b502ccc263663733d72","https://git.kernel.org/stable/c/66ac05e7b0d6bbd1bee9fcf729e20fd4cce86d17"],"products":[],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2025-68331","score":0.00212,"percentile":0.11349,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}