{"schema_version":"1.7.5","id":"CVE-2026-63821","published":"2026-07-19T12:02:18.751Z","modified":"2026-07-29T03:30:30.450079564Z","related":["openSUSE-SU-2026:11339-1"],"summary":"wifi: rtw88: usb: fix memory leaks on USB write failures","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: rtw88: usb: fix memory leaks on USB write failures\n\nWhen rtw_usb_write_port() fails to submit a USB Request Block (URB)\n(e.g., due to device disconnect or ENOMEM), the completion callback is\nnever executed.\n\nCurrently, the driver ignores the return value of rtw_usb_write_port()\nin rtw_usb_write_data() and rtw_usb_tx_agg_skb(). Because these\nfunctions rely on the completion callback to free the socket buffers\n(skbs) and the transaction control block (txcb), a submission failure\nresults in:\n1. A memory leak of the allocated skb in rtw_usb_write_data().\n2. A memory leak of the txcb structure and all aggregated skbs in\n   rtw_usb_tx_agg_skb().\n\nFix this by checking the return value of rtw_usb_write_port(). If it\nfails, explicitly free the skb in rtw_usb_write_data(), and properly\npurge the tx_ack_queue and free the txcb in rtw_usb_tx_agg_skb().\n\nThe issue was discovered in practice during device disconnect/reconnect\nscenarios and memory pressure conditions. Tested by verifying normal TX\noperation continues after the fix without regressions.","affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"a82dfd33d1237f6c0fb8a7077022189d1fc7ec98"},{"fixed":"2b2060c2075a72bc2de43ce5e1b9347d6c5e27bb"},{"fixed":"53fed4061a09755de99c89fdc7fae5b794da455f"},{"fixed":"200d58c851b8f63f77a05570072dd20f79bc3681"},{"fixed":"8206d173d18ef5a077423119f4e9a93cb3a6f4eb"},{"fixed":"6b964941bbfe6e0f18b1a5e008486dbb62df440a"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63821.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.144"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.95"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.38"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.3"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63821.json"}}],"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/200d58c851b8f63f77a05570072dd20f79bc3681"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2b2060c2075a72bc2de43ce5e1b9347d6c5e27bb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/53fed4061a09755de99c89fdc7fae5b794da455f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6b964941bbfe6e0f18b1a5e008486dbb62df440a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8206d173d18ef5a077423119f4e9a93cb3a6f4eb"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63821.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63821"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63821.json"}}