diff --git a/kernel/tkernel/killblock/kill_block.c b/kernel/tkernel/killblock/kill_block.c
index c9063937253581ee35815ba19d2e48df37599b2a..87ca1f0e463b5927fe7cf63bb54e5ad886af7144 100644
--- a/kernel/tkernel/killblock/kill_block.c
+++ b/kernel/tkernel/killblock/kill_block.c
@@ -284,38 +284,81 @@ bool kill_block_whitelist_match(struct task_struct *p, int sig,
 	return match;
 }
 
+static char *kill_block_full_cgrp_path(struct cgroup *cgrp)
+{
+	char *buf = kmalloc(PATH_MAX, GFP_KERNEL);
+
+	if (!buf)
+		return NULL;
+	cgroup_path(cgrp, buf, PATH_MAX);
+	return buf;
+}
+
 static int kill_block_hook_func(int sig, struct kernel_siginfo *info, struct task_struct *t)
 {
 #define KILL_BLOCK_CGRP_PATH_LEN 256
 #define KILL_BLOCK_CGRP_NAME_LEN 128
-	struct cgroup *src_cgrp, *dst_cgrp;
+	struct cgroup_subsys_state *src_css, *dst_css;
 	char src_cgrp_path[KILL_BLOCK_CGRP_PATH_LEN];
 	char dst_cgrp_path[KILL_BLOCK_CGRP_PATH_LEN];
 	char src_cgrp_name[KILL_BLOCK_CGRP_NAME_LEN];
 	char dst_cgrp_name[KILL_BLOCK_CGRP_NAME_LEN];
+	char *src_path = src_cgrp_path;
+	char *dst_path = dst_cgrp_path;
 	int ret = 0;
 	bool block = false;
+	bool got_src = false, got_dst = false;
 
 	if (sig != SIGKILL && sig != SIGTERM)
 		return 0;
 
 	rcu_read_lock();
-	src_cgrp = task_cgroup(current, cpu_cgrp_subsys.id);
-	dst_cgrp = task_cgroup(t, cpu_cgrp_subsys.id);
-	if (src_cgrp && dst_cgrp) {
-		cgroup_path(src_cgrp, src_cgrp_path, KILL_BLOCK_CGRP_PATH_LEN);
-		cgroup_path(dst_cgrp, dst_cgrp_path, KILL_BLOCK_CGRP_PATH_LEN);
-		cgroup_name(src_cgrp, src_cgrp_name, KILL_BLOCK_CGRP_NAME_LEN);
-		cgroup_name(dst_cgrp, dst_cgrp_name, KILL_BLOCK_CGRP_NAME_LEN);
-
-		block = kill_block_whitelist_match(
-			t, sig, src_cgrp_path, src_cgrp_name,
-			dst_cgrp_path, dst_cgrp_name);
-		if (block)
-			ret = -EPERM;
-	}
+	src_css = task_css(current, cpu_cgrp_subsys.id);
+	dst_css = task_css(t, cpu_cgrp_subsys.id);
+	if (src_css && css_tryget_online(src_css))
+		got_src = true;
+	if (dst_css && css_tryget_online(dst_css))
+		got_dst = true;
 	rcu_read_unlock();
 
+	if (!got_src || !got_dst)
+		goto out_put;
+
+	if (cgroup_path(src_css->cgroup, src_cgrp_path,
+			KILL_BLOCK_CGRP_PATH_LEN) < 0)
+		src_cgrp_path[0] = '\0';
+	else if (strlen(src_cgrp_path) == KILL_BLOCK_CGRP_PATH_LEN - 1)
+		src_path = kill_block_full_cgrp_path(src_css->cgroup);
+	if (cgroup_path(dst_css->cgroup, dst_cgrp_path,
+			KILL_BLOCK_CGRP_PATH_LEN) < 0)
+		dst_cgrp_path[0] = '\0';
+	else if (strlen(dst_cgrp_path) == KILL_BLOCK_CGRP_PATH_LEN - 1)
+		dst_path = kill_block_full_cgrp_path(dst_css->cgroup);
+	if (!src_path || !dst_path) {
+		/* fall back to the stack buffers so name matching still runs */
+		src_path = src_cgrp_path;
+		dst_path = dst_cgrp_path;
+	}
+
+	cgroup_name(src_css->cgroup, src_cgrp_name, KILL_BLOCK_CGRP_NAME_LEN);
+	cgroup_name(dst_css->cgroup, dst_cgrp_name, KILL_BLOCK_CGRP_NAME_LEN);
+
+	block = kill_block_whitelist_match(
+		t, sig, src_path, src_cgrp_name,
+		dst_path, dst_cgrp_name);
+	if (block)
+		ret = -EPERM;
+
+	if (src_path != src_cgrp_path)
+		kfree(src_path);
+	if (dst_path != dst_cgrp_path)
+		kfree(dst_path);
+out_put:
+	if (got_src)
+		css_put(src_css);
+	if (got_dst)
+		css_put(dst_css);
+
 	return ret;
 }