summaryrefslogtreecommitdiff
path: root/kernel
diff options
context:
space:
mode:
authorEddy Wu <itseddy0402@gmail.com>2020-11-07 14:47:22 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-11-10 10:22:20 +0100
commit33175e2d8fdf7b07be9691ee7747a3982dcf52cd (patch)
tree4a478e10958b3049ba014e2d61347858a36e92d0 /kernel
parent81f26642406c16bf52015683511c814ecbe2abc3 (diff)
fork: fix copy_process(CLONE_PARENT) race with the exiting ->real_parent
commit b4e00444cab4c3f3fec876dc0cccc8cbb0d1a948 upstream. current->group_leader->exit_signal may change during copy_process() if current->real_parent exits. Move the assignment inside tasklist_lock to avoid the race. Signed-off-by: Eddy Wu <eddy_wu@trendmicro.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/fork.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index a6dc6b3f6a01..5d35be1e0913 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1539,14 +1539,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
/* ok, now we should be set up.. */
p->pid = pid_nr(pid);
if (clone_flags & CLONE_THREAD) {
- p->exit_signal = -1;
p->group_leader = current->group_leader;
p->tgid = current->tgid;
} else {
- if (clone_flags & CLONE_PARENT)
- p->exit_signal = current->group_leader->exit_signal;
- else
- p->exit_signal = (clone_flags & CSIGNAL);
p->group_leader = p;
p->tgid = p->pid;
}
@@ -1591,9 +1586,14 @@ static struct task_struct *copy_process(unsigned long clone_flags,
if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) {
p->real_parent = current->real_parent;
p->parent_exec_id = current->parent_exec_id;
+ if (clone_flags & CLONE_THREAD)
+ p->exit_signal = -1;
+ else
+ p->exit_signal = current->group_leader->exit_signal;
} else {
p->real_parent = current;
p->parent_exec_id = current->self_exec_id;
+ p->exit_signal = (clone_flags & CSIGNAL);
}
spin_lock(&current->sighand->siglock);