CVE-2021-47190

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

perf bpf: Avoid memory leak from perf_env__insert_btf()

perf_env__insert_btf() doesnt insert if a duplicate BTF id is encountered and this causes a memory leak. Modify the function to return a success/error value and then free the memory if insertion didnt happen.

v2. Adds a return -1 when the insertion error occurs in perf_env__fetch_btf. This doesnt affect anything as the result is never checked.

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/11589d3144bc4e272e0aae46ce8156162e99babc
• https://git.kernel.org/stable/c/4924b1f7c46711762fd0e65c135ccfbcfd6ded1f
• https://git.kernel.org/stable/c/642fc22210a5e59d40b1e4d56d21ec3effd401f2
• https://git.kernel.org/stable/c/ab7c3d8d81c511ddfb27823fb07081c96422b56e
• https://git.kernel.org/stable/c/11589d3144bc4e272e0aae46ce8156162e99babc
• https://git.kernel.org/stable/c/4924b1f7c46711762fd0e65c135ccfbcfd6ded1f
• https://git.kernel.org/stable/c/642fc22210a5e59d40b1e4d56d21ec3effd401f2
• https://git.kernel.org/stable/c/ab7c3d8d81c511ddfb27823fb07081c96422b56e