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authorHou Tao <houtao1@huawei.com>2022-08-10 16:05:33 +0800
committerAlexei Starovoitov <ast@kernel.org>2022-08-10 10:12:48 -0700
commitf0d2b2716d71778d0b0c8eaa433c073287d69d93 (patch)
tree6d2d2bbac610157cdfbeaa0538cb75e0f4b7b217 /net
parent3c5f6e698b5c538bbb23cd453b22e1e4922cffd8 (diff)
bpf: Acquire map uref in .init_seq_private for sock{map,hash} iterator
sock_map_iter_attach_target() 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 sock_map_iter_detach_target() as part of bpf_link_release(), or could be released in bpf_map_put_with_uref() as part of bpf_map_release(). 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@huawei.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220810080538.1845898-5-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'net')
-rw-r--r--net/core/sock_map.c20
1 files changed, 19 insertions, 1 deletions
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),
};