On 8/6/22 12:40 AM, Hou Tao wrote:
From: Hou Tao <houtao1@xxxxxxxxxx>
During bpf(BPF_LINK_CREATE), sock_map_iter_attach_target() has already
acquired a map uref, but the uref may be released by bpf_link_release()
during th reading of map iterator.
Fixing it by acquiring an extra map uref in .init_seq_private and
releasing it in .fini_seq_private.
Fixes: 0365351524d7 ("net: Allow iterating sockmap and sockhash")
Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
See my previous reply for some wording issue.
Acked-by: Yonghong Song <yhs@xxxxxx>
---
net/core/sock_map.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)
diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index 028813dfecb0..9a9fb9487d63 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -783,13 +783,22 @@ static int sock_map_init_seq_private(void *priv_data,
{
struct sock_map_seq_info *info = priv_data;
+ bpf_map_inc_with_uref(aux->map);
info->map = aux->map;
return 0;
}
+static void sock_map_fini_seq_private(void *priv_data)
+{
+ struct sock_map_seq_info *info = priv_data;
+
+ bpf_map_put_with_uref(info->map);
+}
+
static const struct bpf_iter_seq_info sock_map_iter_seq_info = {
.seq_ops = &sock_map_seq_ops,
.init_seq_private = sock_map_init_seq_private,
+ .fini_seq_private = sock_map_fini_seq_private,
.seq_priv_size = sizeof(struct sock_map_seq_info),
};
@@ -1369,18 +1378,27 @@ static const struct seq_operations sock_hash_seq_ops = {
};
static int sock_hash_init_seq_private(void *priv_data,
- struct bpf_iter_aux_info *aux)
+ struct bpf_iter_aux_info *aux)
{
struct sock_hash_seq_info *info = priv_data;
+ bpf_map_inc_with_uref(aux->map);
info->map = aux->map;
info->htab = container_of(aux->map, struct bpf_shtab, map);
return 0;
}
+static void sock_hash_fini_seq_private(void *priv_data)
+{
+ struct sock_hash_seq_info *info = priv_data;
+
+ bpf_map_put_with_uref(info->map);
+}
+
static const struct bpf_iter_seq_info sock_hash_iter_seq_info = {
.seq_ops = &sock_hash_seq_ops,
.init_seq_private = sock_hash_init_seq_private,
+ .fini_seq_private = sock_hash_fini_seq_private,
.seq_priv_size = sizeof(struct sock_hash_seq_info),
};
