CVE-2023-53577

/// Technical description

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

bpf, cpumap: Make sure kthread is running before map update returns

The following warning was reported when running stress-mode enabled

xdp_redirect_cpu with some RT threads:

------------[ cut here ]------------

WARNING: CPU: 4 PID: 65 at kernel/bpf/cpumap.c:135

CPU: 4 PID: 65 Comm: kworker/4:1 Not tainted 6.5.0-rc2+ #1

Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)

Workqueue: events cpu_map_kthread_stop

RIP: 0010:put_cpu_map_entry+0xda/0x220

......

Call Trace:

<TASK>

? show_regs+0x65/0x70

? __warn+0xa5/0x240

......

? put_cpu_map_entry+0xda/0x220

cpu_map_kthread_stop+0x41/0x60

process_one_work+0x6b0/0xb80

worker_thread+0x96/0x720

kthread+0x1a5/0x1f0

ret_from_fork+0x3a/0x70

ret_from_fork_asm+0x1b/0x30

</TASK>

The root cause is the same as commit 436901649731 ("bpf: cpumap: Fix memory

leak in cpu_map_update_elem"). The kthread is stopped prematurely by

kthrea

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References