The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 0d459e2ffb541841714839e8228b845458ed3b27 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2024040517-progeny-sturdy-eee3@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 0d459e2ffb541841714839e8228b845458ed3b27 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> Date: Thu, 28 Mar 2024 14:23:55 +0100 Subject: [PATCH] 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@xxxxxxxxxxxxxxx Fixes: 720344340fb9 ("netfilter: nf_tables: GC transaction race with abort path") Reported-by: Kuan-Ting Chen <hexrabbit@xxxxxxxx> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index ffcd3213c335..0d432d0674e1 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -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;
