From 06d1aeb7b686b8b929cf9bff48aedc9dbb88b7c3 Mon Sep 17 00:00:00 2001 From: Michael Adam Date: Mon, 8 Feb 2010 11:01:47 +0100 Subject: [PATCH] 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 (cherry picked from commit a752bbd10d661ebc93b8d51bd583eb62eb00ad18) Fix bug #7314 (registry: creation of sorted subkey record is racy (not atomic)). --- 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 43963db3c29..fe15b4e4618 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: -- 2.34.1