[libc] Fix memory leak in linux/file.cpp

[codefaber]

When LinuxFile object creation error the preallocated buffer leaks.

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[llvmbot]

@llvm/pr-subscribers-libc

Author: None (codefaber)

Changes

When LinuxFile object creation error the preallocated buffer leaks.

---

Full diff: https://github.com/llvm/llvm-project/pull/150801.diff

1 Files Affected:

• (modified) libc/src/__support/File/linux/file.cpp (+1)

diff --git a/libc/src/__support/File/linux/file.cpp b/libc/src/__support/File/linux/file.cpp
index 4594dadf1ccdf..23bc79177a746 100644
--- a/libc/src/__support/File/linux/file.cpp
+++ b/libc/src/__support/File/linux/file.cpp
@@ -165,6 +165,7 @@ ErrorOr<LinuxFile *> create_file_from_fd(int fd, const char *mode) {
   auto *file = new (ac)
       LinuxFile(fd, buffer, File::DEFAULT_BUFFER_SIZE, _IOFBF, true, modeflags);
   if (!ac) {
+    free(buffer);
     return Error(ENOMEM);
   }
   if (do_seek) {

[lntue]

There are other places in this file having similar issue. We should create a Buffer class wrapper to make sure it is cleanup properly with RAII.

[michaelrj-google]

I'm fine with doing that cleanup, but I am also planning on doing a rewrite of FILE in the not too distant future.