From 8038ee3c3e5b59bcd78467686db5270c68544e30 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 28 Mar 2024 14:23:55 +0100 Subject: [PATCH] netfilter: nf_tables: release mutex after nft_gc_seq_end from abort path 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 Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- 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 ccfe13a2899c..1aff934c682b 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -10518,11 +10518,6 @@ 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; } @@ -10539,6 +10534,14 @@ 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;