In the Linux kernel, the following vulnerability has been resolved: tls: make sure to abort the stream if headers are bogus Normally we wait for the socket to buffer up the whole record before we service it. If the socket has a tiny buffer, however, we read out the data sooner, to prevent connection stalls. Make sure that we abort the connection when we find out late that the record is actually invalid. Retrying the parsing is fine in itself but since we copy some more data each time before we parse we can overflow the allocated skb space. Constructing a scenario in which we're under pressure without enough data in the socket to parse the length upfront is quite hard. syzbot figured out a way to do this by serving us the header in small OOB sends, and then filling in the recvbuf with a large normal send. Make sure that tls_rx_msg_size() aborts strp, if we reach an invalid record there's really no way to recover.
History

Sat, 04 Oct 2025 07:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: tls: make sure to abort the stream if headers are bogus Normally we wait for the socket to buffer up the whole record before we service it. If the socket has a tiny buffer, however, we read out the data sooner, to prevent connection stalls. Make sure that we abort the connection when we find out late that the record is actually invalid. Retrying the parsing is fine in itself but since we copy some more data each time before we parse we can overflow the allocated skb space. Constructing a scenario in which we're under pressure without enough data in the socket to parse the length upfront is quite hard. syzbot figured out a way to do this by serving us the header in small OOB sends, and then filling in the recvbuf with a large normal send. Make sure that tls_rx_msg_size() aborts strp, if we reach an invalid record there's really no way to recover.
Title tls: make sure to abort the stream if headers are bogus
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-10-04T07:31:07.871Z

Reserved: 2025-04-16T07:20:57.148Z

Link: CVE-2025-39946

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-10-04T08:15:47.747

Modified: 2025-10-04T08:15:47.747

Link: CVE-2025-39946

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.