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authorHou Tao <houtao1@huawei.com>2022-08-10 10:05:32 +0200
committerAlexei Starovoitov <ast@kernel.org>2022-08-10 19:12:48 +0200
commit3c5f6e698b5c538bbb23cd453b22e1e4922cffd8 (patch)
tree266aa1abc3e616ba1911890060ae4a8fc4a1e320 /net
parentbpf: Acquire map uref in .init_seq_private for hash map iterator (diff)
downloadlinux-3c5f6e698b5c538bbb23cd453b22e1e4922cffd8.tar.xz
linux-3c5f6e698b5c538bbb23cd453b22e1e4922cffd8.zip
bpf: Acquire map uref in .init_seq_private for sock local storage map iterator
bpf_iter_attach_map() acquires a map uref, and the uref may be released before or in the middle of iterating map elements. For example, the uref could be released in bpf_iter_detach_map() as part of bpf_link_release(), or could be released in bpf_map_put_with_uref() as part of bpf_map_release(). So acquiring an extra map uref in bpf_iter_init_sk_storage_map() and releasing it in bpf_iter_fini_sk_storage_map(). Fixes: 5ce6e77c7edf ("bpf: Implement bpf iterator for sock local storage map") Signed-off-by: Hou Tao <houtao1@huawei.com> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/r/20220810080538.1845898-4-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'net')
-rw-r--r--net/core/bpf_sk_storage.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index a25ec93729b9..83b89ba824d7 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -875,10 +875,18 @@ static int bpf_iter_init_sk_storage_map(void *priv_data,
{
struct bpf_iter_seq_sk_storage_map_info *seq_info = priv_data;
+ bpf_map_inc_with_uref(aux->map);
seq_info->map = aux->map;
return 0;
}
+static void bpf_iter_fini_sk_storage_map(void *priv_data)
+{
+ struct bpf_iter_seq_sk_storage_map_info *seq_info = priv_data;
+
+ bpf_map_put_with_uref(seq_info->map);
+}
+
static int bpf_iter_attach_map(struct bpf_prog *prog,
union bpf_iter_link_info *linfo,
struct bpf_iter_aux_info *aux)
@@ -924,7 +932,7 @@ static const struct seq_operations bpf_sk_storage_map_seq_ops = {
static const struct bpf_iter_seq_info iter_seq_info = {
.seq_ops = &bpf_sk_storage_map_seq_ops,
.init_seq_private = bpf_iter_init_sk_storage_map,
- .fini_seq_private = NULL,
+ .fini_seq_private = bpf_iter_fini_sk_storage_map,
.seq_priv_size = sizeof(struct bpf_iter_seq_sk_storage_map_info),
};