CVE-2026-63821
Description
In the Linux kernel, the following vulnerability has been resolved: wifi: rtw88: usb: fix memory leaks on USB write failures When rtw_usb_write_port() fails to submit a USB Request Block (URB) (e.g., due to device disconnect or ENOMEM), the completion callback is never executed. Currently, the driver ignores the return value of rtw_usb_write_port() in rtw_usb_write_data() and rtw_usb_tx_agg_skb(). Because these functions rely on the completion callback to free the socket buffers (skbs) and the transaction control block (txcb), a submission failure results in: 1. A memory leak of the allocated skb in rtw_usb_write_data(). 2. A memory leak of the txcb structure and all aggregated skbs in rtw_usb_tx_agg_skb(). Fix this by checking the return value of rtw_usb_write_port(). If it fails, explicitly free the skb in rtw_usb_write_data(), and properly purge the tx_ack_queue and free the txcb in rtw_usb_tx_agg_skb(). The issue was discovered in practice during device disconnect/reconnect scenarios and memory pressure conditions. Tested by verifying normal TX operation continues after the fix without regressions.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Windows Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-63821
- https://git.kernel.org/stable/c/200d58c851b8f63f77a05570072dd20f79bc3681
- https://git.kernel.org/stable/c/2b2060c2075a72bc2de43ce5e1b9347d6c5e27bb
- https://git.kernel.org/stable/c/53fed4061a09755de99c89fdc7fae5b794da455f
- https://git.kernel.org/stable/c/6b964941bbfe6e0f18b1a5e008486dbb62df440a
- https://git.kernel.org/stable/c/8206d173d18ef5a077423119f4e9a93cb3a6f4eb
- https://www.suse.com/security/cve/CVE-2026-63821.html
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.