From 70b971118e074d5042715587953f27929e99117a Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Wed, 16 Sep 2020 13:44:53 -0700 Subject: [PATCH] bpf: Use hlist_add_head_rcu when linking to local_storage The local_storage->list will be traversed by rcu reader in parallel. Thus, hlist_add_head_rcu() is needed in bpf_selem_link_storage_nolock(). This patch fixes it. This part of the code has recently been refactored in bpf-next and this patch makes changes to the new file "bpf_local_storage.c". Instead of using the original offending commit in the Fixes tag, the commit that created the file "bpf_local_storage.c" is used. A separate fix has been provided to the bpf tree. Fixes: 450af8d0f6be ("bpf: Split bpf_local_storage to bpf_sk_storage") Signed-off-by: Martin KaFai Lau Signed-off-by: Daniel Borkmann Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20200916204453.2003915-1-kafai@fb.com --- kernel/bpf/bpf_local_storage.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c index ffa7d11fc2bd..5d3a7af9ba9b 100644 --- a/kernel/bpf/bpf_local_storage.c +++ b/kernel/bpf/bpf_local_storage.c @@ -159,7 +159,7 @@ void bpf_selem_link_storage_nolock(struct bpf_local_storage *local_storage, struct bpf_local_storage_elem *selem) { RCU_INIT_POINTER(selem->local_storage, local_storage); - hlist_add_head(&selem->snode, &local_storage->list); + hlist_add_head_rcu(&selem->snode, &local_storage->list); } void bpf_selem_unlink_map(struct bpf_local_storage_elem *selem)