5.4-stable review patch. If anyone has any objections, please let me know.
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From: Pablo Neira Ayuso pablo@netfilter.org
commit 0d459e2ffb541841714839e8228b845458ed3b27 upstream.
The commit mutex should not be released during the critical section between nft_gc_seq_begin() and nft_gc_seq_end(), otherwise, async GC worker could collect expired objects and get the released commit lock within the same GC sequence.
nf_tables_module_autoload() temporarily releases the mutex to load module dependencies, then it goes back to replay the transaction again. Move it at the end of the abort phase after nft_gc_seq_end() is called.
Cc: stable@vger.kernel.org Fixes: 720344340fb9 ("netfilter: nf_tables: GC transaction race with abort path") Reported-by: Kuan-Ting Chen hexrabbit@devco.re 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, 8 insertions(+), 5 deletions(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index b719f3517caf1..8dd7efb3b8f7b 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -7696,11 +7696,6 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) nf_tables_abort_release(trans); }
- if (action == NFNL_ABORT_AUTOLOAD) - nf_tables_module_autoload(net); - else - nf_tables_module_autoload_cleanup(net); - return err; }
@@ -7717,6 +7712,14 @@ static int nf_tables_abort(struct net *net, struct sk_buff *skb,
WARN_ON_ONCE(!list_empty(&nft_net->commit_list));
+ /* module autoload needs to happen after GC sequence update because it + * temporarily releases and grabs mutex again. + */ + if (action == NFNL_ABORT_AUTOLOAD) + nf_tables_module_autoload(net); + else + nf_tables_module_autoload_cleanup(net); + mutex_unlock(&nft_net->commit_mutex);
return ret;