Masahiro Yamada be2fa44b51 genksyms: fix memory leak when the same symbol is read from *.symref file
When a symbol that is already registered is read again from *.symref
file, __add_symbol() removes the previous one from the hash table without
freeing it.

[Test Case]

  $ cat foo.c
  #include <linux/export.h>
  void foo(void);
  void foo(void) {}
  EXPORT_SYMBOL(foo);

  $ cat foo.symref
  foo void foo ( void )
  foo void foo ( void )

When a symbol is removed from the hash table, it must be freed along
with its ->name and ->defn members. However, sym->name cannot be freed
because it is sometimes shared with node->string, but not always. If
sym->name and node->string share the same memory, free(sym->name) could
lead to a double-free bug.

To resolve this issue, always assign a strdup'ed string to sym->name.

Fixes: 64e6c1e123 ("genksyms: track symbol checksum changes")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-01-10 23:01:22 +09:00
2024-09-01 20:43:24 -07:00
2022-09-28 09:02:20 +02:00
2025-01-05 14:13:40 -08:00
2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
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