CVE-2023-54316

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> refscale: Fix uninitalized use of wait_queue_head_t<br /> <br /> Running the refscale test occasionally crashes the kernel with the<br /> following error:<br /> <br /> [ 8569.952896] BUG: unable to handle page fault for address: ffffffffffffffe8<br /> [ 8569.952900] #PF: supervisor read access in kernel mode<br /> [ 8569.952902] #PF: error_code(0x0000) - not-present page<br /> [ 8569.952904] PGD c4b048067 P4D c4b049067 PUD c4b04b067 PMD 0<br /> [ 8569.952910] Oops: 0000 [#1] PREEMPT_RT SMP NOPTI<br /> [ 8569.952916] Hardware name: Dell Inc. PowerEdge R750/0WMWCR, BIOS 1.2.4 05/28/2021<br /> [ 8569.952917] RIP: 0010:prepare_to_wait_event+0x101/0x190<br /> :<br /> [ 8569.952940] Call Trace:<br /> [ 8569.952941] <br /> [ 8569.952944] ref_scale_reader+0x380/0x4a0 [refscale]<br /> [ 8569.952959] kthread+0x10e/0x130<br /> [ 8569.952966] ret_from_fork+0x1f/0x30<br /> [ 8569.952973] <br /> <br /> The likely cause is that init_waitqueue_head() is called after the call to<br /> the torture_create_kthread() function that creates the ref_scale_reader<br /> kthread. Although this init_waitqueue_head() call will very likely<br /> complete before this kthread is created and starts running, it is<br /> possible that the calling kthread will be delayed between the calls to<br /> torture_create_kthread() and init_waitqueue_head(). In this case, the<br /> new kthread will use the waitqueue head before it is properly initialized,<br /> which is not good for the kernel&amp;#39;s health and well-being.<br /> <br /> The above crash happened here:<br /> <br /> static inline void __add_wait_queue(...)<br /> {<br /> :<br /> if (!(wq-&gt;flags &amp; WQ_FLAG_PRIORITY))