@@ -202,6 +202,10 @@ std::optional<int64_t> get_tablet_id(std::string file_path) {
         return std::nullopt;
     }
 
+    if (data_prefix.length() + data_pos >= path_view.length()) {
+        return std::nullopt;
+    }
+
     // Extract the part after "data/"
     path_view = path_view.substr(data_pos + data_prefix.length() + 1);
 
 
@@ -19,6 +19,7 @@
 // and modified by Doris
 
 #include "block_file_cache_test_common.h"
+#include "olap/olap_define.h"
 
 namespace doris::io {
 
@@ -7416,6 +7417,13 @@ TEST_F(BlockFileCacheTest, reader_dryrun_when_download_file_cache) {
     config::enable_reader_dryrun_when_download_file_cache = org;
 }
 
+TEST_F(BlockFileCacheTest, cached_remote_file_reader_tablet_id_guard) {
+    // Ensure get_tablet_id gracefully returns nullopt
+    std::string fake_path = "/mnt/data";
+    auto tablet_id = get_tablet_id(fake_path);
+    EXPECT_FALSE(tablet_id.has_value());
+}
+
 void move_dir_to_version1(const std::string& dirPath) {
     try {
         // layer 1
 
@@ -54,7 +54,7 @@ suite("test_file_cache_info") {
             `c_mktsegment` string NULL
         )
         DUPLICATE KEY(`c_custkey`)
-        DISTRIBUTED BY HASH(`c_custkey`) BUCKETS 1  // only 1 tablet
+        DISTRIBUTED BY HASH(`c_custkey`) BUCKETS 1
         PROPERTIES (
             "file_cache_ttl_seconds" = "3600"
         )
@@ -126,4 +126,5 @@ suite("test_file_cache_info") {
     }
 
     }
-}
+}
+
Original file line number	Diff line number	Diff line change
`@@ -202,6 +202,10 @@ std::optional<int64_t> get_tablet_id(std::string file_path) {`
`202`	`202`	`return std::nullopt;`
`203`	`203`	`}`
`204`	`204`
	`205`	`+ if (data_prefix.length() + data_pos >= path_view.length()) {`
	`206`	`+ return std::nullopt;`
	`207`	`+ }`
	`208`	`+`
`205`	`209`	`// Extract the part after "data/"`
`206`	`210`	`path_view = path_view.substr(data_pos + data_prefix.length() + 1);`
`207`	`211`
Original file line number	Diff line number	Diff line change
`@@ -54,7 +54,7 @@ suite("test_file_cache_info") {`
`54`	`54`	`c_mktsegment` string NULL
`55`	`55`	`)`
`56`	`56`	DUPLICATE KEY(`c_custkey`)
`57`		- DISTRIBUTED BY HASH(`c_custkey`) BUCKETS 1 // only 1 tablet
	`57`	+ DISTRIBUTED BY HASH(`c_custkey`) BUCKETS 1
`58`	`58`	`PROPERTIES (`
`59`	`59`	`"file_cache_ttl_seconds" = "3600"`
`60`	`60`	`)`
`@@ -126,4 +126,5 @@ suite("test_file_cache_info") {`
`126`	`126`	`}`
`127`	`127`
`128`	`128`	`}`
`129`		`-}`
	`129`	`+}`
	`130`	`+`