diff options
| author | Ralf Lici <ralf@mandelbit.com> | 2026-03-25 19:49:18 +0300 |
|---|---|---|
| committer | Antonio Quartulli <antonio@openvpn.net> | 2026-05-05 01:31:06 +0300 |
| commit | c539cb30f93f119566f2ae9d016cce11f188d780 (patch) | |
| tree | 656c6a69256f0b6a665854c7c8fb2d008de0a6fe | |
| parent | a200cdbf95932631ec338d08a6e9e31b34c4e8a6 (diff) | |
| download | linux-c539cb30f93f119566f2ae9d016cce11f188d780.tar.xz | |
ovpn: ensure packet delivery happens with BH disabled
ovpn injects decrypted packets into the netdev RX path through
ovpn_netdev_write() which invokes gro_cells_receive() and
dev_dstats_rx_add().
ovpn_netdev_write() is normally called in softirq context,
however, in case of TCP connections it may also be invoked
process context.
When this happens gro_cells_receive() will throw a warning:
[ 230.183747][ T12] WARNING: net/core/gro_cells.c:30 at gro_cells_receive+0x708/0xaa0, CPU#1: kworker/u16:0/12
and lockdep will also report a potential inconsistent lock state:
WARNING: inconsistent lock state
7.0.0-rc4+ #246 Tainted: G W
--------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
because attempts to acquire gro_cells->bh_lock by both
contexts may lead to a deadlock.
At the same time, dev_dstats_rx_add() does not expect to race
with a softirq (which may happen when invoked in process context),
because the latter may access its per-cpu state and corrupt
it.
Fix all this by invoking local_bh_disable/enable() around
gro_cells_receive() and dev_dstats_rx_add() to ensure that
bottom halves are always disabled before calling both of
them.
Fixes: 11851cbd60ea ("ovpn: implement TCP transport")
Signed-off-by: Ralf Lici <ralf@mandelbit.com>
Signed-off-by: Antonio Quartulli <antonio@openvpn.net>
| -rw-r--r-- | drivers/net/ovpn/io.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/net/ovpn/io.c b/drivers/net/ovpn/io.c index d92bb87be2b2..22c555dd962e 100644 --- a/drivers/net/ovpn/io.c +++ b/drivers/net/ovpn/io.c @@ -91,12 +91,18 @@ static void ovpn_netdev_write(struct ovpn_peer *peer, struct sk_buff *skb) /* cause packet to be "received" by the interface */ pkt_len = skb->len; + /* we may get here in process context in case of TCP connections, + * therefore we have to disable BHs to ensure gro_cells_receive() + * and dev_dstats_rx_add() do not get corrupted or enter deadlock + */ + local_bh_disable(); ret = gro_cells_receive(&peer->ovpn->gro_cells, skb); if (likely(ret == NET_RX_SUCCESS)) { /* update RX stats with the size of decrypted packet */ ovpn_peer_stats_increment_rx(&peer->vpn_stats, pkt_len); dev_dstats_rx_add(peer->ovpn->dev, pkt_len); } + local_bh_enable(); } void ovpn_decrypt_post(void *data, int ret) |