Description
In the Linux kernel, the following vulnerability has been resolved: mm/mempolicy: fix memory leaks in weighted_interleave_auto_store() weighted_interleave_auto_store() fetches old_wi_state inside the if (!input) block only. This causes two memory leaks: 1. When a user writes "false" and the current mode is already manual, the function returns early without freeing the freshly allocated new_wi_state. 2. When a user writes "true", old_wi_state stays NULL because the fetch is skipped entirely. The old state is then overwritten by rcu_assign_pointer() but never freed, since the cleanup path is gated on old_wi_state being non-NULL. A user can trigger this repeatedly by writing "1" in a loop. Fix both leaks by moving the old_wi_state fetch before the input check, making it unconditional. This also allows a unified early return for both "true" and "false" when the requested mode matches the current mode. Reviewed by: Donet Tom <donettom@linux.ibm.com>
Product status
e341f9c3c8412e57fe0042a33a2640245ecdf619 (git) before c42a7efb9060d89b72708ffaf255d0002c2164a7
e341f9c3c8412e57fe0042a33a2640245ecdf619 (git) before 39caa9ca863f96b3d00447c5aa200cabda489856
e341f9c3c8412e57fe0042a33a2640245ecdf619 (git) before 6fae274ce0e3109cbbc4c18b354eaace1f0af7d7
6.16
Any version before 6.16
6.18.27 (semver)
7.0.4 (semver)
7.1-rc1 (original_commit_for_fix)
References
git.kernel.org/...c/c42a7efb9060d89b72708ffaf255d0002c2164a7
git.kernel.org/...c/39caa9ca863f96b3d00447c5aa200cabda489856
git.kernel.org/...c/6fae274ce0e3109cbbc4c18b354eaace1f0af7d7