diff options
author | Hou Tao <houtao1@huawei.com> | 2022-08-10 16:05:33 +0800 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2022-08-10 10:12:48 -0700 |
commit | f0d2b2716d71778d0b0c8eaa433c073287d69d93 (patch) | |
tree | 6d2d2bbac610157cdfbeaa0538cb75e0f4b7b217 /net/core | |
parent | 3c5f6e698b5c538bbb23cd453b22e1e4922cffd8 (diff) | |
download | linux-f0d2b2716d71778d0b0c8eaa433c073287d69d93.tar.gz linux-f0d2b2716d71778d0b0c8eaa433c073287d69d93.tar.bz2 linux-f0d2b2716d71778d0b0c8eaa433c073287d69d93.zip |
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/core')
-rw-r--r-- | net/core/sock_map.c | 20 |
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), }; |