From: Florian Westphal <fw@xxxxxxxxx> If userspace program exits while the queue its subscribed to has packets those need to be discarded. commit dc21c6cc3d69 ("netfilter: nfnetlink_queue: acquire rcu_read_lock() in instance_destroy_rcu()") fixed a (harmless) rcu splat that could be triggered in this case. Add a test case to cover this. Signed-off-by: Florian Westphal <fw@xxxxxxxxx> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> --- .../selftests/net/netfilter/nft_queue.sh | 37 +++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/tools/testing/selftests/net/netfilter/nft_queue.sh b/tools/testing/selftests/net/netfilter/nft_queue.sh index 8538f08c64c2..c61d23a8c88d 100755 --- a/tools/testing/selftests/net/netfilter/nft_queue.sh +++ b/tools/testing/selftests/net/netfilter/nft_queue.sh @@ -375,6 +375,42 @@ EOF wait 2>/dev/null } +test_queue_removal() +{ + read tainted_then < /proc/sys/kernel/tainted + + ip netns exec "$ns1" nft -f - <<EOF +flush ruleset +table ip filter { + chain output { + type filter hook output priority 0; policy accept; + ip protocol icmp queue num 0 + } +} +EOF + ip netns exec "$ns1" ./nf_queue -q 0 -d 30000 -t "$timeout" & + local nfqpid=$! + + busywait "$BUSYWAIT_TIMEOUT" nf_queue_wait "$ns1" 0 + + ip netns exec "$ns1" ping -w 2 -f -c 10 127.0.0.1 -q >/dev/null + kill $nfqpid + + ip netns exec "$ns1" nft flush ruleset + + if [ "$tainted_then" -ne 0 ];then + return + fi + + read tainted_now < /proc/sys/kernel/tainted + if [ "$tainted_now" -eq 0 ];then + echo "PASS: queue program exiting while packets queued" + else + echo "TAINT: queue program exiting while packets queued" + ret=1 + fi +} + ip netns exec "$nsrouter" sysctl net.ipv6.conf.all.forwarding=1 > /dev/null ip netns exec "$nsrouter" sysctl net.ipv4.conf.veth0.forwarding=1 > /dev/null ip netns exec "$nsrouter" sysctl net.ipv4.conf.veth1.forwarding=1 > /dev/null @@ -413,5 +449,6 @@ test_tcp_localhost test_tcp_localhost_connectclose test_tcp_localhost_requeue test_icmp_vrf +test_queue_removal exit $ret -- 2.30.2