Messages in this thread Patch in this message | | | From | "Eric W. Biederman" <> | Date | Wed, 22 May 2019 19:38:56 -0500 | Subject | [REVIEW][PATCH 06/26] signal/pid_namespace: Fix reboot_pid_ns to use send_sig not force_sig |
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The locking in force_sig_info is not prepared to deal with a task that exits or execs (as sighand may change). The is not a locking problem in force_sig 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 confusing and 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: Daniel Lezcano <daniel.lezcano@free.fr> Cc: Serge Hallyn <serge@hallyn.com> Cc: Oleg Nesterov <oleg@redhat.com> Fixes: cf3f89214ef6 ("pidns: add reboot_pid_ns() to handle the reboot syscall") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> --- kernel/pid_namespace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index aa6e72fb7c08..098233ebe589 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -325,7 +325,7 @@ int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd) } read_lock(&tasklist_lock); - force_sig(SIGKILL, pid_ns->child_reaper); + send_sig(SIGKILL, pid_ns->child_reaper, 1); read_unlock(&tasklist_lock); do_exit(0); -- 2.21.0
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