ProcFS: Reads past the end of a generated file should be zero-length

1 files changed, 10 insertions, 7 deletions

diff --git a/Kernel/FileSystem/ProcFS.cpp b/Kernel/FileSystem/ProcFS.cpp
index 79cf40e494..900fd69f26 100644
--- a/Kernel/FileSystem/ProcFS.cpp
+++ b/Kernel/FileSystem/ProcFS.cpp
@@ -1107,13 +1107,16 @@ ssize_t ProcFSInode::read_bytes(off_t offset, ssize_t count, u8* buffer, FileDes
     }
 
     auto& data = generated_data;
-    ssize_t nread = 0;
-    if (data.has_value()) {
-        nread = min(static_cast<off_t>(data.value().size() - offset), static_cast<off_t>(count));
-        memcpy(buffer, data.value().data() + offset, nread);
-        if (nread == 0 && description && description->generator_cache())
-            description->generator_cache().clear();
-    }
+    if (!data.has_value())
+        return 0;
+
+    if ((size_t)offset >= data.value().size())
+        return 0;
+
+    ssize_t nread = min(static_cast<off_t>(data.value().size() - offset), static_cast<off_t>(count));
+    memcpy(buffer, data.value().data() + offset, nread);
+    if (nread == 0 && description && description->generator_cache())
+        description->generator_cache().clear();
 
     return nread;
 }