6.6-stable review patch. If anyone has any objections, please let me know.
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From: Florian Westphal fw@strlen.de
[ 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@strlen.de Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/netfilter/nf_tables_api.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)
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); }