netfilter: nf_tables: release mutex after nft_gc_seq_end from abort path

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: 720344340f ("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>
This commit is contained in:
Pablo Neira Ayuso 2024-03-28 14:23:55 +01:00
parent a45e688957
commit 0d459e2ffb
1 changed files with 8 additions and 5 deletions

View File

@ -10651,11 +10651,6 @@ 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;
}
@ -10672,6 +10667,14 @@ 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;