From 539ad6e6f9a067646a018d77582af0babf8e125e Mon Sep 17 00:00:00 2001 From: Logan Gunthorpe Date: Tue, 4 Jun 2024 10:38:37 -0600 Subject: [PATCH 103/201] mdadm: Block SIGCHLD processes before starting children There is a small race condition noticed during code review, but never actully hit in practice, with the write_zero feature. If a write zeros fork finishes quickly before wait_for_zero_forks() gets called, then the SIGCHLD will be delivered before the signalfd is setup. While this is only theoretical, fix this by blocking the SIGCHLD signal before forking any children. Signed-off-by: Logan Gunthorpe Signed-off-by: Mariusz Tkaczyk --- Create.c | 1 + 1 file changed, 1 insertion(+) diff --git a/Create.c b/Create.c index 4f992a22..bd4875e4 100644 --- a/Create.c +++ b/Create.c @@ -401,6 +401,7 @@ static int add_disks(int mdfd, struct mdinfo *info, struct shape *s, */ sigemptyset(&sigset); sigaddset(&sigset, SIGINT); + sigaddset(&sigset, SIGCHLD); sigprocmask(SIG_BLOCK, &sigset, &orig_sigset); memset(zero_pids, 0, sizeof(zero_pids)); -- 2.41.0