FS: JFS: Check for read-only mounted filesystem in txBegin

This patch adds a check for read-only mounted filesystem in txBegin before starting a transaction potentially saving from NULL pointer deref. Signed-off-by: Immad Mir <mirimmad17@gmail.com> Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
kleikamp · Jun 23, 2023 · 95e2b35 · 95e2b35
1 parent 47cfdc3
commit 95e2b35
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/fs/jfs/jfs_txnmgr.c b/fs/jfs/jfs_txnmgr.c
@@ -354,6 +354,11 @@ tid_t txBegin(struct super_block *sb, int flag)
 	jfs_info("txBegin: flag = 0x%x", flag);
 	log = JFS_SBI(sb)->log;
 
+	if (!log) {
+		jfs_error(sb, "read-only filesystem\n");
+		return 0;
+	}
+
 	TXN_LOCK();
 
 	INCREMENT(TxStat.txBegin);