CVE-2024-57886

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

mm/damon/core: fix new damon_target objects leaks on damon_commit_targets()

Patch series mm/damon/core: fix memory leaks and ignored inputs from damon_commit_ctx().

Due to two bugs in damon_commit_targets() and damon_commit_schemes(), which are called from damon_commit_ctx(), some user inputs can be ignored, and some mmeory objects can be leaked. Fix those.

Note that only DAMON sysfs interface users are affected. Other DAMON core API user modules that more focused more on simple and dedicated production usages, including DAMON_RECLAIM and DAMON_LRU_SORT are not using the buggy function in the way, so not affected.

This patch (of 2):

When new DAMON targets are added via damon_commit_targets(), the newly created targets are not deallocated when updating the internal data (damon_commit_target()) is failed. Worse yet, even if the setup is successfully done, the new target is not linked to the context. Hence, the new targets are always leaked regardless of the internal data setup failure. Fix the leaks.

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/3647932d0b3e609c762c55e8f9fe10a09776e0a7
• https://git.kernel.org/stable/c/8debfc5b1aa569d3d2ac836af2553da037611c61