From: Eric Dumazet Date: Tue, 21 Jul 2026 10:12:40 +0000 (+0000) Subject: net: hsr: fix memory leak on slave unregistration by removing synced VLANs X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=dcf15eaf5641812f1cfc5e96537380132a7da89d;p=thirdparty%2Fkernel%2Flinux.git net: hsr: fix memory leak on slave unregistration by removing synced VLANs When an HSR master device is brought UP, it auto-adds VLAN 0 via vlan_vid0_add(), which propagates VID 0 to its slave devices (slave A and B). If a slave device is later unregistered while HSR is active (e.g., during netns cleanup or interface destruction), hsr_del_port() is called to detach the slave port from the HSR master. However, hsr_del_port() currently does not delete the VLAN IDs that were synced to the slave device by HSR. As a result, the slave device retains a refcount on VID 0 (and any other synced VLANs). When the slave device is destroyed, its vlan_info / vlan_vid_info structure remains allocated, leading to a memory leak. Fix this by calling vlan_vids_del_by_dev(port->dev, master->dev) in hsr_del_port() before unlinking slave A or slave B ports, matching the propagation logic in hsr_ndo_vlan_rx_add_vid() / hsr_ndo_vlan_rx_kill_vid() and the cleanup behavior in bonding and team drivers. Fixes: 1a8a63a5305e ("net: hsr: Add VLAN CTAG filter support") Reported-by: syzbot+456957213f32970c0762@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6a4cb6ca.57639fcc.86d58.000b.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Reviewed-by: Fernando Fernandez Mancera Reviewed-by: Felix Maurer Link: https://patch.msgid.link/20260721101240.995597-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- diff --git a/net/hsr/hsr_slave.c b/net/hsr/hsr_slave.c index d9af9e65f72f0..01c73b4b50ddd 100644 --- a/net/hsr/hsr_slave.c +++ b/net/hsr/hsr_slave.c @@ -242,6 +242,8 @@ void hsr_del_port(struct hsr_port *port) netdev_rx_handler_unregister(port->dev); if (!port->hsr->fwd_offloaded) dev_set_promiscuity(port->dev, -1); + if (port->type == HSR_PT_SLAVE_A || port->type == HSR_PT_SLAVE_B) + vlan_vids_del_by_dev(port->dev, master->dev); netdev_upper_dev_unlink(port->dev, master->dev); if (hsr->prot_version == PRP_V1 && port->type == HSR_PT_SLAVE_B) {