This is a note to let you know that I've just added the patch titled
netfilter: nf_tables: must hold rcu read lock while iterating object type list
to the 6.6-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:
netfilter-nf_tables-must-hold-rcu-read-lock-while-it.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 938f574aacdbb82f1500105e4498662da80c1170
Author: Florian Westphal <fw@xxxxxxxxx>
Date: Mon Nov 4 10:41:19 2024 +0100
netfilter: nf_tables: must hold rcu read lock while iterating object type list
[ Upstream commit cddc04275f95ca3b18da5c0fb111705ac173af89 ]
Update of stateful object triggers:
WARNING: suspicious RCU usage
net/netfilter/nf_tables_api.c:7759 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by nft/3060:
#0: ffff88810f0578c8 (&nft_net->commit_mutex){+.+.}-{4:4}, [..]
... but this list is not protected by the transaction mutex but the
nfnl nftables subsystem mutex.
Switch to nft_obj_type_get which will acquire rcu read lock,
bump refcount, and returns the result.
v3: Dan Carpenter points out nft_obj_type_get returns error pointer, not
NULL, on error.
Fixes: dad3bdeef45f ("netfilter: nf_tables: fix memory leak during stateful obj update").
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index abab78148c6c8..eee7997048fb9 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -7615,9 +7615,7 @@ static int nf_tables_updobj(const struct nft_ctx *ctx,
struct nft_trans *trans;
int err = -ENOMEM;
- if (!try_module_get(type->owner))
- return -ENOENT;
-
+ /* caller must have obtained type->owner reference. */
trans = nft_trans_alloc(ctx, NFT_MSG_NEWOBJ,
sizeof(struct nft_trans_obj));
if (!trans)
@@ -7685,15 +7683,16 @@ static int nf_tables_newobj(struct sk_buff *skb, const struct nfnl_info *info,
if (info->nlh->nlmsg_flags & NLM_F_REPLACE)
return -EOPNOTSUPP;
- type = __nft_obj_type_get(objtype, family);
- if (WARN_ON_ONCE(!type))
- return -ENOENT;
-
if (!obj->ops->update)
return 0;
+ type = nft_obj_type_get(net, objtype, family);
+ if (WARN_ON_ONCE(IS_ERR(type)))
+ return PTR_ERR(type);
+
nft_ctx_init(&ctx, net, skb, info->nlh, family, table, NULL, nla);
+ /* type->owner reference is put when transaction object is released. */
return nf_tables_updobj(&ctx, type, nla[NFTA_OBJ_DATA], obj);
}
