CVE-2025-37756

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+0x109/0x280 net/socket.c:1045

__sys_recvfrom+0x202/0x380 net/socket.c:2237