Commit 331a109f91ea ("libsemanage: fsync final files before rename")
added fsync() for policy files and improved situation when something
unexpected happens right after rename(). However the module store could
be affected as well. After the following steps module files could be 0
size:
1. Run `semanage fcontext -a -t var_t "/tmp/abc"`
2. Force shutdown the server during the command is run, or right after
it's finished
3. Boot the system and look for empty files:
# find /var/lib/selinux/targeted/ -type f -size 0 | wc -l
1266
It looks like this situation can be avoided if the filesystem with the
sandbox is sync()ed before we start to rename() directories in the
store.
Signed-off-by: Petr Lautrbach <plautrba@xxxxxxxxxx>
---
- syncfs() moved before rename() dance
libsemanage/src/semanage_store.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/libsemanage/src/semanage_store.c b/libsemanage/src/semanage_store.c
index cd5e46bb2401..c6a736fe2d26 100644
--- a/libsemanage/src/semanage_store.c
+++ b/libsemanage/src/semanage_store.c
@@ -1736,6 +1736,19 @@ static int semanage_commit_sandbox(semanage_handle_t * sh)
}
close(fd);
+ /* sync changes in sandbox to filesystem */
+ fd = open(sandbox, O_DIRECTORY);
+ if (fd == -1) {
+ ERR(sh, "Error while opening %s for syncfs(): %d", sandbox, errno);
+ return -1;
+ }
+ if (syncfs(fd) == -1) {
+ ERR(sh, "Error while syncing %s to filesystem: %d", sandbox, errno);
+ close(fd);
+ return -1;
+ }
+ close(fd);
+
retval = commit_number;
if (semanage_get_active_lock(sh) < 0) {
--
2.30.0
