CVE-2025-37756

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

net: tls: explicitly disallow disconnect

syzbot discovered that it can disconnect a TLS socket and then

run into all sort of unexpected corner cases. I have a vague

recollection of Eric pointing this out to us a long time ago.

Supporting disconnect is really hard, for one thing if offload

is enabled we'd need to wait for all packets to be _acked_.

Disconnect is not commonly used, disallow it.

The immediate problem syzbot run into is the warning in the strp,

but that's just the easiest bug to trigger:

WARNING: CPU: 0 PID: 5834 at net/tls/tls_strp.c:486 tls_strp_msg_load+0x72e/0xa80 net/tls/tls_strp.c:486

RIP: 0010:tls_strp_msg_load+0x72e/0xa80 net/tls/tls_strp.c:486

Call Trace:

<TASK>

tls_rx_rec_wait+0x280/0xa60 net/tls/tls_sw.c:1363

tls_sw_recvmsg+0x85c/0x1c30 net/tls/tls_sw.c:2043

inet6_recvmsg+0x2c9/0x730 net/ipv6/af_inet6.c:678

sock_recvmsg_nosec net/socket.c:1023 [inline]

sock_recvmsg+0x

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References