CVE-2026-46042: linux kernel vulnerability

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
CVE-2026-46042CVSS 5.5Linux

CVE-2026-46042: linux kernel vulnerability

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>

CVSS
5.5 MEDIUM
EPSS
2.66%
Known exploited
not in KEV
Product
linux kernel

What is known

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>

Sources

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