Merge tag 'probes-fixes-v6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull fprobe fix from Masami Hiramatsu:

 - allocate entry_data_size buffer for each rethook instance.

   This fixes a buffer overrun bug (which leads a kernel crash)
   when fprobe user uses its entry_data in the entry_handler.

* tag 'probes-fixes-v6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  fprobe: Fix to allocate entry_data_size buffer with rethook instances

Author: torvalds

kernel/trace/fprobe.c

@@ -189,25 +189,23 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
 {
 	int size;
 
-	if (num <= 0)
-		return -EINVAL;
-
 	if (!fp->exit_handler) {
 		fp->rethook = NULL;
 		return 0;
 	}
 
 	/* Initialize rethook if needed */
 	if (fp->nr_maxactive)
-		size = fp->nr_maxactive;
+		num = fp->nr_maxactive;
 	else
-		size = num * num_possible_cpus() * 2;
-	if (size <= 0)
+		num *= num_possible_cpus() * 2;
+	if (num <= 0)
 		return -EINVAL;
 
+	size = sizeof(struct fprobe_rethook_node) + fp->entry_data_size;
+
 	/* Initialize rethook */
-	fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler,
-				sizeof(struct fprobe_rethook_node), size);
+	fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler, size, num);
 	if (IS_ERR(fp->rethook))
 		return PTR_ERR(fp->rethook);