From 7b91929ba0422435c193c506dbaa593964be6e84 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Fri, 17 Mar 2017 19:20:04 -0400 Subject: [PATCH] run-command: fix segfault when cleaning forked async process Callers of the run-command API may mark a child as "clean_on_exit"; it gets added to a list and killed when the main process dies. Since commit 46df6906f (execv_dashed_external: wait for child on signal death, 2017-01-06), we respect an extra "wait_after_clean" flag, which we expect to find in the child_process struct. When Git is built with NO_PTHREADS, we start "struct async" processes by forking rather than spawning a thread. The resulting processes get added to the cleanup list but they don't have a child_process struct, and the cleanup function ends up dereferencing NULL. We should notice this case and assume that the processes do not need to be waited for (i.e., the same behavior they had before 46df6906f). Reported-by: Brandon Williams Signed-off-by: Jeff King Reviewed-by: Jonathan Nieder Signed-off-by: Junio C Hamano --- run-command.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/run-command.c b/run-command.c index 73bfba7ef9..7dc8a8e70e 100644 --- a/run-command.c +++ b/run-command.c @@ -48,7 +48,7 @@ static void cleanup_children(int sig, int in_signal) kill(p->pid, sig); - if (p->process->wait_after_clean) { + if (p->process && p->process->wait_after_clean) { p->next = children_to_wait_for; children_to_wait_for = p; } else {