This is a note to let you know that I've just added the patch titled
bpf: Acquire map uref in .init_seq_private for sock{map,hash} iterator
to the 5.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bpf-acquire-map-uref-in-.init_seq_private-for-sock-map-hash-iterator.patch
and it can be found in the queue-5.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f0d2b2716d71778d0b0c8eaa433c073287d69d93 Mon Sep 17 00:00:00 2001
From: Hou Tao <houtao1@xxxxxxxxxx>
Date: Wed, 10 Aug 2022 16:05:33 +0800
Subject: bpf: Acquire map uref in .init_seq_private for sock{map,hash} iterator
From: Hou Tao <houtao1@xxxxxxxxxx>
commit f0d2b2716d71778d0b0c8eaa433c073287d69d93 upstream.
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@xxxxxxxxxx>
Acked-by: Yonghong Song <yhs@xxxxxx>
Link: https://lore.kernel.org/r/20220810080538.1845898-5-houtao@xxxxxxxxxxxxxxx
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/core/sock_map.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -783,13 +783,22 @@ static int sock_map_init_seq_private(voi
{
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_
};
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),
};
Patches currently in stable-queue which might be from houtao1@xxxxxxxxxx are
queue-5.19/bpf-acquire-map-uref-in-.init_seq_private-for-array-map-iterator.patch
queue-5.19/bpf-acquire-map-uref-in-.init_seq_private-for-sock-map-hash-iterator.patch
queue-5.19/bpf-acquire-map-uref-in-.init_seq_private-for-hash-map-iterator.patch
queue-5.19/bpf-acquire-map-uref-in-.init_seq_private-for-sock-local-storage-map-iterator.patch
queue-5.19/bpf-check-the-validity-of-max_rdwr_access-for-sock-local-storage-map-iterator.patch
