CVE-2022-49779

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> kprobes: Skip clearing aggrprobe&amp;#39;s post_handler in kprobe-on-ftrace case<br /> <br /> In __unregister_kprobe_top(), if the currently unregistered probe has<br /> post_handler but other child probes of the aggrprobe do not have<br /> post_handler, the post_handler of the aggrprobe is cleared. If this is<br /> a ftrace-based probe, there is a problem. In later calls to<br /> disarm_kprobe(), we will use kprobe_ftrace_ops because post_handler is<br /> NULL. But we&amp;#39;re armed with kprobe_ipmodify_ops. This triggers a WARN in<br /> __disarm_kprobe_ftrace() and may even cause use-after-free:<br /> <br /> Failed to disarm kprobe-ftrace at kernel_clone+0x0/0x3c0 (error -2)<br /> WARNING: CPU: 5 PID: 137 at kernel/kprobes.c:1135 __disarm_kprobe_ftrace.isra.21+0xcf/0xe0<br /> Modules linked in: testKprobe_007(-)<br /> CPU: 5 PID: 137 Comm: rmmod Not tainted 6.1.0-rc4-dirty #18<br /> [...]<br /> Call Trace:<br /> <br /> __disable_kprobe+0xcd/0xe0<br /> __unregister_kprobe_top+0x12/0x150<br /> ? mutex_lock+0xe/0x30<br /> unregister_kprobes.part.23+0x31/0xa0<br /> unregister_kprobe+0x32/0x40<br /> __x64_sys_delete_module+0x15e/0x260<br /> ? do_user_addr_fault+0x2cd/0x6b0<br /> do_syscall_64+0x3a/0x90<br /> entry_SYSCALL_64_after_hwframe+0x63/0xcd<br /> [...]<br /> <br /> For the kprobe-on-ftrace case, we keep the post_handler setting to<br /> identify this aggrprobe armed with kprobe_ipmodify_ops. This way we<br /> can disarm it correctly.