CVE-2021-47519

In the Linux kernel, the following vulnerability has been resolved:

can: m_can: m_can_read_fifo: fix memory leak in error branch

In m_can_read_fifo(), if the second call to m_can_fifo_read() fails, the function jump to the out_fail label and returns without calling m_can_receive_skb(). This means that the skb previously allocated by alloc_can_skb() is not freed. In other terms, this is a memory leak.

This patch adds a goto label to destroy the skb if an error occurs.

Issue was found with GCC -fanalyzer, please follow the link below for details.

Weakness

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

Affected Software

Potential Mitigations

• Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
• For example, glibc in Linux provides protection against free of invalid pointers.
• When using Xcode to target OS X or iOS, enable automatic reference counting (ARC) [REF-391].
• To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std::auto_ptr (defined by ISO/IEC ISO/IEC 14882:2003), std::shared_ptr and std::unique_ptr (specified by an upcoming revision of the C++ standard, informally referred to as C++ 1x), or equivalent solutions such as Boost.

References

• https://git.kernel.org/stable/c/31cb32a590d62b18f69a9a6d433f4e69c74fdd56
• https://git.kernel.org/stable/c/75a422165477dd12d2d20aa7c9ee7c9a281c9908
• https://git.kernel.org/stable/c/31cb32a590d62b18f69a9a6d433f4e69c74fdd56
• https://git.kernel.org/stable/c/75a422165477dd12d2d20aa7c9ee7c9a281c9908