libext2fs: fix coverity nits in tdb.c

Address unchecked returned value and a string not null terminated warnings.

Addresses-Coverity-Bug: 709473
Addresses-Coverity-Bug: 709474
Addresses-Coverity-Bug: 1464578
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/lib/ext2fs/tdb.c b/lib/ext2fs/tdb.c
index dc5c0ff..b07b291 100644 (file)
--- a/lib/ext2fs/tdb.c
+++ b/lib/ext2fs/tdb.c
@@ -3089,9 +3089,10 @@ void tdb_increment_seqnum_nonblock(struct tdb_context *tdb)
        /* we ignore errors from this, as we have no sane way of
           dealing with them.
        */
-       tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum);
+       if (tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum) == -1)
+               return;
        seqnum++;
-       tdb_ofs_write(tdb, TDB_SEQNUM_OFS, &seqnum);
+       (void) tdb_ofs_write(tdb, TDB_SEQNUM_OFS, &seqnum);
 }
 
 /*
@@ -3692,7 +3693,8 @@ int tdb_get_seqnum(struct tdb_context *tdb)
 {
        tdb_off_t seqnum=0;
 
-       tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum);
+       if (tdb_ofs_read(tdb, TDB_SEQNUM_OFS, &seqnum) == -1)
+               return 0;
        return seqnum;
 }
 
@@ -3914,7 +3916,8 @@ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
        }
 
        if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
-           || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0
+           || memcmp(tdb->header.magic_food, TDB_MAGIC_FOOD,
+                     sizeof(TDB_MAGIC_FOOD)) != 0
            || (tdb->header.version != TDB_VERSION
                && !(rev = (tdb->header.version==TDB_BYTEREV(TDB_VERSION))))) {
                /* its not a valid database - possibly initialise it */