journald: remove rotated file from hashmap when rotation fails

Before, when the user journal file was rotated, journal_file_rotate
could close the old file and fail to open the new file. In that
case, we would leave the old (deallocated) file in the hashmap.
On subsequent accesses, we could retrieve this stale entry, leading
to a segfault.

When journal_file_rotate fails with the file pointer set to 0,
old file is certainly gone, and cannot be used anymore.

https://bugzilla.redhat.com/show_bug.cgi?id=890463

diff --git a/src/journal/journald-server.c b/src/journal/journald-server.c
index 4f47eb1c11ccdee5fa2a13507afc8c57f14c2e02..e03e413aeffba6fc337912d6d56bd77dfca5e9a4 100644 (file)
--- a/src/journal/journald-server.c
+++ b/src/journal/journald-server.c
@@ -321,8 +321,10 @@ void server_rotate(Server *s) {
                 if (r < 0)
                         if (f)
                                 log_error("Failed to rotate %s: %s", f->path, strerror(-r));
-                        else
+                        else {
                                 log_error("Failed to create user journal: %s", strerror(-r));
+                                hashmap_remove(s->user_journals, k);
+                        }
                 else {
                         hashmap_replace(s->user_journals, k, f);
                         server_fix_perms(s, f, PTR_TO_UINT32(k));