The locking in force_sig_info is not prepared to deal with
a task that exits or execs (as sighand may change). As force_sig
is only built to handle synchronous exceptions.
Further the function force_sig_info changes the signal state if the
signal is ignored, or blocked or if SIGNAL_UNKILLABLE will prevent the
delivery of the signal. The signal SIGKILL can not be ignored and can
not be blocked and SIGNAL_UNKILLABLE won't prevent it from being
delivered.
So using force_sig rather than send_sig for SIGKILL is pointless.
Because it won't impact the sending of the signal and and because
using force_sig is wrong, replace force_sig with send_sig.
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Fixes: d2ba09c17a06 ("net: add skeleton of bpfilter kernel module")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
1dfd1711de