fork: fix copy_process(CLONE_PARENT) race with the exiting ->real_parent
authorEddy Wu <itseddy0402@gmail.com>
Sat, 7 Nov 2020 06:47:22 +0000 (14:47 +0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sun, 8 Nov 2020 19:18:39 +0000 (11:18 -0800)
commitb4e00444cab4c3f3fec876dc0cccc8cbb0d1a948
tree72e12c5023507b955eed888011eca19f579a38ed
parent9dbc1c03eeb534b82647cccb059aca0685d449a7
fork: fix copy_process(CLONE_PARENT) race with the exiting ->real_parent

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>
kernel/fork.c