From: Samanta Navarro <ferivoz@riseup.net>
Date: Sun, 4 Sep 2022 11:58:03 +0000 (+0000)
Subject: copy_tree: do not block on fifos
X-Git-Tag: 4.13~20
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=10cd68e0f04b48363eb32d2c6e168b358fb27810;p=thirdparty%2Fshadow.git

copy_tree: do not block on fifos

Fixes regression introduced in faeab50e710131816b261de66141524898c2c487.

If a directory contains fifos, then openat blocks until the other side
of the fifo is connected as well.

This means that users can prevent "usermod -m" from completing if their
home directories contain at least one fifo.
---

diff --git a/libmisc/copydir.c b/libmisc/copydir.c
index b6025f4c7..5fb47da01 100644
--- a/libmisc/copydir.c
+++ b/libmisc/copydir.c
@@ -126,12 +126,12 @@ static int perm_copy_path(const struct path_info *src,
 {
 	int src_fd, dst_fd, ret;
 
-	src_fd = openat(src->dirfd, src->name, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
+	src_fd = openat(src->dirfd, src->name, O_RDONLY | O_NOFOLLOW | O_NONBLOCK | O_CLOEXEC);
 	if (src_fd < 0) {
 		return -1;
 	}
 
-	dst_fd = openat(dst->dirfd, dst->name, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
+	dst_fd = openat(dst->dirfd, dst->name, O_RDONLY | O_NOFOLLOW | O_NONBLOCK | O_CLOEXEC);
 	if (dst_fd < 0) {
 		(void) close (src_fd);
 		return -1;
@@ -152,12 +152,12 @@ static int attr_copy_path(const struct path_info *src,
 {
 	int src_fd, dst_fd, ret;
 
-	src_fd = openat(src->dirfd, src->name, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
+	src_fd = openat(src->dirfd, src->name, O_RDONLY | O_NOFOLLOW | O_NONBLOCK | O_CLOEXEC);
 	if (src_fd < 0) {
 		return -1;
 	}
 
-	dst_fd = openat(dst->dirfd, dst->name, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
+	dst_fd = openat(dst->dirfd, dst->name, O_RDONLY | O_NOFOLLOW | O_NONBLOCK | O_CLOEXEC);
 	if (dst_fd < 0) {
 		(void) close (src_fd);
 		return -1;