CVE-2025-39736

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> mm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak_lock<br /> <br /> When netpoll is enabled, calling pr_warn_once() while holding<br /> kmemleak_lock in mem_pool_alloc() can cause a deadlock due to lock<br /> inversion with the netconsole subsystem. This occurs because<br /> pr_warn_once() may trigger netpoll, which eventually leads to<br /> __alloc_skb() and back into kmemleak code, attempting to reacquire<br /> kmemleak_lock.<br /> <br /> This is the path for the deadlock.<br /> <br /> mem_pool_alloc()<br /> -&gt; raw_spin_lock_irqsave(&amp;kmemleak_lock, flags);<br /> -&gt; pr_warn_once()<br /> -&gt; netconsole subsystem<br /> -&gt; netpoll<br /> -&gt; __alloc_skb<br /> -&gt; __create_object<br /> -&gt; raw_spin_lock_irqsave(&amp;kmemleak_lock, flags);<br /> <br /> Fix this by setting a flag and issuing the pr_warn_once() after<br /> kmemleak_lock is released.