CVE-2021-47496

In the Linux kernel, the following vulnerability has been resolved:
net/tls: Fix flipped sign in tls_err_abort() calls sk->sk_err appears to
expect a positive value, a convention that ktls doesn’t always follow and
that leads to memory corruption in other code. For instance, [kworker]
tls_encrypt_done(…, err=<negative error from crypto request>)
tls_err_abort(…, err) sk->sk_err = err; [task] splice_from_pipe_feed …
tls_sw_do_sendpage if (sk->sk_err) { ret = -sk->sk_err; // ret is positive
splice_from_pipe_feed (continued) ret = actor(…) // ret is still positive
and interpreted as bytes // written, resulting in underflow of buf->len and
// sd->len, leading to huge buf->offset and bogus // addresses computed in
later calls to actor() Fix all tls_err_abort() callers to pass a negative
error code consistently and centralize the error-prone sign flip there,
throwing in a warning to catch future misuse and uninlining the function so
it really does only warn once.