From a752bbd10d661ebc93b8d51bd583eb62eb00ad18 Mon Sep 17 00:00:00 2001 From: Michael Adam Date: Mon, 8 Feb 2010 11:01:47 +0100 Subject: s3:registry: eliminate race condition in creating/scanning sorted subkeys Called, from key_exists, scan_sorted_subkeys re-creates the sorted subkeys record of the given key and then searches through it. The race is that between creation and parsing of the sorted subkey record, another process that stores some other subkey of the same parent key will delete the sorted subkey record, resulting in an WERR_BADFILE of an operation that should actually succeed. This patch fixes the issue by wrapping the creation and parsing into a transaction. Michael --- source3/registry/reg_backend_db.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/source3/registry/reg_backend_db.c b/source3/registry/reg_backend_db.c index 43963db3c2..fe15b4e461 100644 --- a/source3/registry/reg_backend_db.c +++ b/source3/registry/reg_backend_db.c @@ -1368,14 +1368,31 @@ static bool scan_parent_subkeys(struct db_context *db, const char *parent, if (state.scanned) { result = state.found; } else { + res = db->transaction_start(db); + if (res != 0) { + DEBUG(0, ("error starting transacion\n")); + goto fail; + } + if (!create_sorted_subkeys(path, key)) { + res = db->transaction_cancel(db); + if (res != 0) { + smb_panic("Failed to cancel transaction."); + } goto fail; } + res = db->parse_record(db, string_term_tdb_data(key), parent_subkey_scanner, &state); if ((res == 0) && (state.scanned)) { result = state.found; } + + res = db->transaction_commit(db); + if (res != 0) { + DEBUG(0, ("error committing transaction\n")); + result = false; + } } fail: -- cgit