Re: [PATCH net] net: sctp: check proc_dointvec result in proc_sctp_do_auth

From: Daniel Borkmann <redacted>
Date: Wed, 18 Jun 2014 23:46:31 +0200

When writing to the sysctl field net.sctp.auth_enable, it can well
be that the user buffer we handed over to proc_dointvec() via
proc_sctp_do_auth() handler contains something other than integers.

In that case, we would set an uninitialized 4-byte value from the
stack to net->sctp.auth_enable that can be leaked back when reading
the sysctl variable, and it can unintentionally turn auth_enable
on/off based on the stack content since auth_enable is interpreted
as a boolean.

Fix it up by making sure proc_dointvec() returned sucessfully.

Fixes: b14878ccb7fa ("net: sctp: cache auth_enable per endpoint")
Reported-by: Florian Westphal <redacted>
Signed-off-by: Daniel Borkmann <redacted>

Applied, thanks Daniel.