From 75673fda0c557ae26078177dd14d4857afbf128d Mon Sep 17 00:00:00 2001
From: Brandon Kammerdiener <brandon.kammerdiener@intel.com>
Date: Thu, 24 Apr 2025 11:32:51 -0400
Subject: [PATCH] bpf: fix possible endless loop in BPF map iteration
The _safe variant used here gets the next element before running the callback,
avoiding the endless loop condition.
Signed-off-by: Brandon Kammerdiener <brandon.kammerdiener@intel.com>
Link: https://lore.kernel.org/r/20250424153246.141677-2-brandon.kammerdiener@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Hou Tao <houtao1@huawei.com>
---
kernel/bpf/hashtab.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 5a5adc66b8e22..92b606d600207 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -2189,7 +2189,7 @@ static long bpf_for_each_hash_elem(struct bpf_map *map, bpf_callback_t callback_
b = &htab->buckets[i];
rcu_read_lock();
head = &b->head;
- hlist_nulls_for_each_entry_rcu(elem, n, head, hash_node) {
+ hlist_nulls_for_each_entry_safe(elem, n, head, hash_node) {
key = elem->key;
if (is_percpu) {
/* current cpu value for percpu map */