lib-index: Detect broken log_file_tail_offset updates without assert-crashing.

diff --git a/src/lib-index/mail-transaction-log-file.c b/src/lib-index/mail-transaction-log-file.c
index 8e11cc8f6ce90df77b16a28284bf25be861b01e8..4fb3e393c016bd8297b5552cd096a9a02c771e50 100644 (file)
--- a/src/lib-index/mail-transaction-log-file.c
+++ b/src/lib-index/mail-transaction-log-file.c
@@ -935,10 +935,11 @@ int mail_transaction_log_file_open(struct mail_transaction_log_file *file)
 
 static int
 log_file_track_mailbox_sync_offset_hdr(struct mail_transaction_log_file *file,
-                                      const void *data, unsigned int size)
+                                      const void *data, unsigned int trans_size)
 {
        const struct mail_transaction_header_update *u = data;
        const struct mail_index_header *ihdr;
+       const unsigned int size = trans_size - sizeof(struct mail_transaction_header);
        const unsigned int offset_pos =
                offsetof(struct mail_index_header, log_file_tail_offset);
        const unsigned int offset_size = sizeof(ihdr->log_file_tail_offset);
@@ -961,6 +962,10 @@ log_file_track_mailbox_sync_offset_hdr(struct mail_transaction_log_file *file,
                if (tail_offset < file->saved_tail_offset) {
                        /* ignore shrinking tail offsets */
                        return 1;
+               } else if (tail_offset > file->sync_offset + trans_size) {
+                       mail_transaction_log_file_set_corrupted(file,
+                               "log_file_tail_offset %u goes past sync offset %"PRIuUOFF_T,
+                               tail_offset, file->sync_offset + trans_size);
                } else {
                        file->saved_tail_offset = tail_offset;
                        if (tail_offset > file->max_tail_offset)
@@ -1277,8 +1282,7 @@ log_file_track_sync(struct mail_transaction_log_file *file,
        case MAIL_TRANSACTION_HEADER_UPDATE:
                /* see if this updates mailbox_sync_offset */
                ret = log_file_track_mailbox_sync_offset_hdr(file, data,
-                                                            trans_size -
-                                                            sizeof(*hdr));
+                                                            trans_size);
                if (ret != 0)
                        return ret < 0 ? -1 : 1;
                break;