* [PATCH net-next v2 1/2] rtnetlink: pass extack to ndo_bridge_getlink()
2026-09-12 13:50 [PATCH net-next v2 0/2] bridge: report an oversized IFLA_AF_SPEC nest instead of truncating Artem Lytkin
@ 2026-09-12 13:50 ` Artem Lytkin
2026-09-12 13:50 ` [PATCH net-next v2 2/2] net: bridge: fail link info that does not fit the IFLA_AF_SPEC nest Artem Lytkin
1 sibling, 0 replies; 3+ messages in thread
From: Artem Lytkin @ 2026-09-12 13:50 UTC (permalink / raw)
To: netdev
Cc: bridge, razor, idosch, davem, edumazet, kuba, pabeni, horms,
andrew+netdev, kuniyu, michael.chan, pavan.chebbi, ajit.khaparde,
sriharsha.basavapatna, anthony.l.nguyen, przemyslaw.kitszel,
intel-wired-lan, saeedm, tariqt, mbloch, oss-drivers, wintera,
aswin, linux-s390
Let the bridge report why it could not fill in the link info for a
port. rtnl_bridge_getlink() passes the dump extack, rtnl_bridge_notify()
gets one from its setlink and dellink callers.
No functional change.
Assisted-by: Claude:claude-opus-5
Signed-off-by: Artem Lytkin <iprintercanon@gmail.com>
---
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 4 ++--
drivers/net/ethernet/emulex/benet/be_main.c | 4 ++--
drivers/net/ethernet/intel/i40e/i40e_main.c | 6 ++++--
drivers/net/ethernet/intel/ice/ice_main.c | 6 ++++--
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 5 +++--
.../net/ethernet/mellanox/mlx5/core/en_main.c | 4 ++--
.../ethernet/netronome/nfp/nfp_net_common.c | 4 ++--
drivers/s390/net/qeth_l2_main.c | 4 ++--
include/linux/netdevice.h | 5 +++--
include/linux/rtnetlink.h | 3 ++-
net/bridge/br_netlink.c | 3 ++-
net/bridge/br_private.h | 2 +-
net/core/rtnetlink.c | 18 +++++++++++-------
13 files changed, 40 insertions(+), 28 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index ca99f4b1a63c3..a752e66bf6368 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -16154,12 +16154,12 @@ static const struct udp_tunnel_nic_info bnxt_udp_tunnels = {
static int bnxt_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
struct net_device *dev, u32 filter_mask,
- int nlflags)
+ int nlflags, struct netlink_ext_ack *extack)
{
struct bnxt *bp = netdev_priv(dev);
return ndo_dflt_bridge_getlink(skb, pid, seq, dev, bp->br_mode, 0, 0,
- nlflags, filter_mask, NULL);
+ nlflags, filter_mask, NULL, extack);
}
static int bnxt_bridge_setlink(struct net_device *dev, struct nlmsghdr *nlh,
diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index ed302f5ec4768..cc9c87539a429 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -5011,7 +5011,7 @@ static int be_ndo_bridge_setlink(struct net_device *dev, struct nlmsghdr *nlh,
static int be_ndo_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
struct net_device *dev, u32 filter_mask,
- int nlflags)
+ int nlflags, struct netlink_ext_ack *extack)
{
struct be_adapter *adapter = netdev_priv(dev);
int status = 0;
@@ -5037,7 +5037,7 @@ static int be_ndo_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
return ndo_dflt_bridge_getlink(skb, pid, seq, dev,
hsw_mode == PORT_FWD_TYPE_VEPA ?
BRIDGE_MODE_VEPA : BRIDGE_MODE_VEB,
- 0, 0, nlflags, filter_mask, NULL);
+ 0, 0, nlflags, filter_mask, NULL, extack);
}
static struct be_cmd_work *be_alloc_work(struct be_adapter *adapter,
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index abbc71e815ae3..52c2b393aacd2 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -13151,6 +13151,7 @@ static int i40e_ndo_bridge_setlink(struct net_device *dev,
* @dev: the netdev being configured
* @filter_mask: unused
* @nlflags: netlink flags passed in
+ * @extack: netlink extended ack
*
* Return the mode in which the hardware bridge is operating in
* i.e VEB or VEPA.
@@ -13158,7 +13159,8 @@ static int i40e_ndo_bridge_setlink(struct net_device *dev,
static int i40e_ndo_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
struct net_device *dev,
u32 __always_unused filter_mask,
- int nlflags)
+ int nlflags,
+ struct netlink_ext_ack *extack)
{
struct i40e_netdev_priv *np = netdev_priv(dev);
struct i40e_vsi *vsi = np->vsi;
@@ -13175,7 +13177,7 @@ static int i40e_ndo_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
return 0;
return ndo_dflt_bridge_getlink(skb, pid, seq, dev, veb->bridge_mode,
- 0, 0, nlflags, filter_mask, NULL);
+ 0, 0, nlflags, filter_mask, NULL, extack);
}
/**
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index fe47ec0ba8094..038ce1fe5bfe5 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -8086,12 +8086,14 @@ int ice_set_rss_hfunc(struct ice_vsi *vsi, u8 hfunc)
* @dev: the netdev being configured
* @filter_mask: filter mask passed in
* @nlflags: netlink flags passed in
+ * @extack: netlink extended ack
*
* Return the bridge mode (VEB/VEPA)
*/
static int
ice_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
- struct net_device *dev, u32 filter_mask, int nlflags)
+ struct net_device *dev, u32 filter_mask, int nlflags,
+ struct netlink_ext_ack *extack)
{
struct ice_pf *pf = ice_netdev_to_pf(dev);
u16 bmode;
@@ -8099,7 +8101,7 @@ ice_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
bmode = pf->first_sw->bridge_mode;
return ndo_dflt_bridge_getlink(skb, pid, seq, dev, bmode, 0, 0, nlflags,
- filter_mask, NULL);
+ filter_mask, NULL, extack);
}
/**
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index f91856498eb2d..77dfd80a6e368 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -10726,7 +10726,8 @@ static int ixgbe_ndo_bridge_setlink(struct net_device *dev,
static int ixgbe_ndo_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
struct net_device *dev,
- u32 filter_mask, int nlflags)
+ u32 filter_mask, int nlflags,
+ struct netlink_ext_ack *extack)
{
struct ixgbe_adapter *adapter = ixgbe_from_netdev(dev);
@@ -10735,7 +10736,7 @@ static int ixgbe_ndo_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
return ndo_dflt_bridge_getlink(skb, pid, seq, dev,
adapter->bridge_mode, 0, 0, nlflags,
- filter_mask, NULL);
+ filter_mask, NULL, extack);
}
static void *ixgbe_fwd_add(struct net_device *pdev, struct net_device *vdev)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index fc110a7d16e8d..53bf79dbe08de 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -5277,7 +5277,7 @@ static int mlx5e_xdp(struct net_device *dev, struct netdev_bpf *xdp)
#ifdef CONFIG_MLX5_ESWITCH
static int mlx5e_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
struct net_device *dev, u32 filter_mask,
- int nlflags)
+ int nlflags, struct netlink_ext_ack *extack)
{
struct mlx5e_priv *priv = netdev_priv(dev);
struct mlx5_core_dev *mdev = priv->mdev;
@@ -5288,7 +5288,7 @@ static int mlx5e_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
mode = setting ? BRIDGE_MODE_VEPA : BRIDGE_MODE_VEB;
return ndo_dflt_bridge_getlink(skb, pid, seq, dev,
mode,
- 0, 0, nlflags, filter_mask, NULL);
+ 0, 0, nlflags, filter_mask, NULL, extack);
}
static int mlx5e_bridge_setlink(struct net_device *dev, struct nlmsghdr *nlh,
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index 7928e76da723e..cb751dddb6887 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -2257,7 +2257,7 @@ static int nfp_net_set_mac_address(struct net_device *netdev, void *addr)
static int nfp_net_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
struct net_device *dev, u32 filter_mask,
- int nlflags)
+ int nlflags, struct netlink_ext_ack *extack)
{
struct nfp_net *nn = netdev_priv(dev);
u16 mode;
@@ -2269,7 +2269,7 @@ static int nfp_net_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
BRIDGE_MODE_VEPA : BRIDGE_MODE_VEB;
return ndo_dflt_bridge_getlink(skb, pid, seq, dev, mode, 0, 0,
- nlflags, filter_mask, NULL);
+ nlflags, filter_mask, NULL, extack);
}
static int nfp_net_bridge_setlink(struct net_device *dev, struct nlmsghdr *nlh,
diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 2935c2ecc314b..f960cf5a97a29 100644
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -935,7 +935,7 @@ static void qeth_l2_br2dev_put(void)
static int qeth_l2_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
struct net_device *dev, u32 filter_mask,
- int nlflags)
+ int nlflags, struct netlink_ext_ack *extack)
{
struct qeth_priv *priv = netdev_priv(dev);
struct qeth_card *card = dev->ml_priv;
@@ -949,7 +949,7 @@ static int qeth_l2_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
return ndo_dflt_bridge_getlink(skb, pid, seq, dev,
mode, priv->brport_features,
priv->brport_hw_features,
- nlflags, filter_mask, NULL);
+ nlflags, filter_mask, NULL, extack);
}
static const struct nla_policy qeth_brport_policy[IFLA_BRPORT_MAX + 1] = {
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 707b2e51c2b97..18a03f0f6f113 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1360,7 +1360,7 @@ struct netdev_net_notifier {
* u16 flags, struct netlink_ext_ack *extack)
* int (*ndo_bridge_getlink)(struct sk_buff *skb, u32 pid, u32 seq,
* struct net_device *dev, u32 filter_mask,
- * int nlflags)
+ * int nlflags, struct netlink_ext_ack *extack)
* int (*ndo_bridge_dellink)(struct net_device *dev, struct nlmsghdr *nlh,
* u16 flags);
*
@@ -1659,7 +1659,8 @@ struct net_device_ops {
u32 pid, u32 seq,
struct net_device *dev,
u32 filter_mask,
- int nlflags);
+ int nlflags,
+ struct netlink_ext_ack *extack);
int (*ndo_bridge_dellink)(struct net_device *dev,
struct nlmsghdr *nlh,
u16 flags);
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 95729339e7a54..a408c36a7b558 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -222,7 +222,8 @@ extern int ndo_dflt_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
u32 filter_mask,
int (*vlan_fill)(struct sk_buff *skb,
struct net_device *dev,
- u32 filter_mask));
+ u32 filter_mask),
+ struct netlink_ext_ack *extack);
extern void rtnl_offload_xstats_notify(struct net_device *dev);
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index ae76df0de05a0..855a46aec3a89 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -680,7 +680,8 @@ void br_ifinfo_notify(int event, const struct net_bridge *br,
* Dump information about all ports, in response to GETLINK
*/
int br_getlink(struct sk_buff *skb, u32 pid, u32 seq,
- struct net_device *dev, u32 filter_mask, int nlflags)
+ struct net_device *dev, u32 filter_mask, int nlflags,
+ struct netlink_ext_ack *extack)
{
struct net_bridge_port *port = br_port_get_rtnl(dev);
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 09c397e303307..edbe7a1f57363 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -2179,7 +2179,7 @@ int br_setlink(struct net_device *dev, struct nlmsghdr *nlmsg, u16 flags,
struct netlink_ext_ack *extack);
int br_dellink(struct net_device *dev, struct nlmsghdr *nlmsg, u16 flags);
int br_getlink(struct sk_buff *skb, u32 pid, u32 seq, struct net_device *dev,
- u32 filter_mask, int nlflags);
+ u32 filter_mask, int nlflags, struct netlink_ext_ack *extack);
int br_process_vlan_info(struct net_bridge *br,
struct net_bridge_port *p, int cmd,
struct bridge_vlan_info *vinfo_curr,
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index be9d1625bac31..967b587ef6648 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -5398,7 +5398,8 @@ int ndo_dflt_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
u32 filter_mask,
int (*vlan_fill)(struct sk_buff *skb,
struct net_device *dev,
- u32 filter_mask))
+ u32 filter_mask),
+ struct netlink_ext_ack *extack)
{
struct nlmsghdr *nlh;
struct ifinfomsg *ifm;
@@ -5574,7 +5575,8 @@ static int rtnl_bridge_getlink(struct sk_buff *skb, struct netlink_callback *cb)
if (idx >= cb->args[0]) {
err = br_dev->netdev_ops->ndo_bridge_getlink(
skb, portid, seq, dev,
- filter_mask, NLM_F_MULTI);
+ filter_mask, NLM_F_MULTI,
+ cb->extack);
if (err < 0 && err != -EOPNOTSUPP) {
if (likely(skb->len))
break;
@@ -5590,7 +5592,8 @@ static int rtnl_bridge_getlink(struct sk_buff *skb, struct netlink_callback *cb)
err = ops->ndo_bridge_getlink(skb, portid,
seq, dev,
filter_mask,
- NLM_F_MULTI);
+ NLM_F_MULTI,
+ cb->extack);
if (err < 0 && err != -EOPNOTSUPP) {
if (likely(skb->len))
break;
@@ -5624,7 +5627,8 @@ static inline size_t bridge_nlmsg_size(void)
+ nla_total_size(sizeof(u16)); /* IFLA_BRIDGE_MODE */
}
-static int rtnl_bridge_notify(struct net_device *dev)
+static int rtnl_bridge_notify(struct net_device *dev,
+ struct netlink_ext_ack *extack)
{
struct net *net = dev_net(dev);
struct sk_buff *skb;
@@ -5639,7 +5643,7 @@ static int rtnl_bridge_notify(struct net_device *dev)
goto errout;
}
- err = dev->netdev_ops->ndo_bridge_getlink(skb, 0, 0, dev, 0, 0);
+ err = dev->netdev_ops->ndo_bridge_getlink(skb, 0, 0, dev, 0, 0, extack);
if (err < 0)
goto errout;
@@ -5730,7 +5734,7 @@ static int rtnl_bridge_setlink(struct sk_buff *skb, struct nlmsghdr *nlh,
/* Generate event to notify upper layer of bridge
* change
*/
- err = rtnl_bridge_notify(dev);
+ err = rtnl_bridge_notify(dev, extack);
}
}
@@ -5805,7 +5809,7 @@ static int rtnl_bridge_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
/* Generate event to notify upper layer of bridge
* change
*/
- err = rtnl_bridge_notify(dev);
+ err = rtnl_bridge_notify(dev, extack);
}
}
--
2.43.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH net-next v2 2/2] net: bridge: fail link info that does not fit the IFLA_AF_SPEC nest
2026-09-12 13:50 [PATCH net-next v2 0/2] bridge: report an oversized IFLA_AF_SPEC nest instead of truncating Artem Lytkin
2026-09-12 13:50 ` [PATCH net-next v2 1/2] rtnetlink: pass extack to ndo_bridge_getlink() Artem Lytkin
@ 2026-09-12 13:50 ` Artem Lytkin
1 sibling, 0 replies; 3+ messages in thread
From: Artem Lytkin @ 2026-09-12 13:50 UTC (permalink / raw)
To: netdev
Cc: bridge, razor, idosch, davem, edumazet, kuba, pabeni, horms,
andrew+netdev, kuniyu, michael.chan, pavan.chebbi, ajit.khaparde,
sriharsha.basavapatna, anthony.l.nguyen, przemyslaw.kitszel,
intel-wired-lan, saeedm, tariqt, mbloch, oss-drivers, wintera,
aswin, linux-s390
br_fill_ifinfo() puts all of a port's VLAN, tunnel and MST entries into
one nest, and nla_len is a u16, so a large enough port produces a nest
whose length wraps and userspace reads garbage.
Cancel the message and return -E2BIG with an extack pointing at
RTM_GETVLAN instead. The dump retries the port with an empty skb and
the error goes to userspace; notifications reach rtnl_set_sk_err() and
listeners resync. Not -EMSGSIZE, since no bigger buffer would help.
Assisted-by: Claude:claude-opus-5
Signed-off-by: Artem Lytkin <iprintercanon@gmail.com>
---
net/bridge/br_netlink.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 855a46aec3a89..53676df9e4d11 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -459,7 +459,7 @@ static int br_fill_ifinfo(struct sk_buff *skb,
const struct net_bridge_port *port,
u32 pid, u32 seq, int event, unsigned int flags,
u32 filter_mask, const struct net_device *dev,
- bool getlink)
+ bool getlink, struct netlink_ext_ack *extack)
{
u8 operstate = netif_running(dev) ? READ_ONCE(dev->operstate) :
IF_OPER_DOWN;
@@ -613,6 +613,12 @@ static int br_fill_ifinfo(struct sk_buff *skb,
done:
if (af) {
+ if (skb_tail_pointer(skb) - (unsigned char *)af > U16_MAX) {
+ NL_SET_ERR_MSG_MOD(extack,
+ "VLAN information does not fit in one message, use RTM_GETVLAN");
+ nlmsg_cancel(skb, nlh);
+ return -E2BIG;
+ }
if (nlmsg_get_pos(skb) - (void *)af > nla_attr_size(0))
nla_nest_end(skb, af);
else
@@ -654,7 +660,8 @@ void br_info_notify(int event, const struct net_bridge *br,
if (skb == NULL)
goto errout;
- err = br_fill_ifinfo(skb, port, 0, 0, event, 0, filter, dev, false);
+ err = br_fill_ifinfo(skb, port, 0, 0, event, 0, filter, dev, false,
+ NULL);
if (err < 0) {
/* -EMSGSIZE implies BUG in br_nlmsg_size() */
WARN_ON(err == -EMSGSIZE);
@@ -693,7 +700,7 @@ int br_getlink(struct sk_buff *skb, u32 pid, u32 seq,
return 0;
return br_fill_ifinfo(skb, port, pid, seq, RTM_NEWLINK, nlflags,
- filter_mask, dev, true);
+ filter_mask, dev, true, extack);
}
static int br_vlan_info(struct net_bridge *br, struct net_bridge_port *p,
--
2.43.0
^ permalink raw reply related [flat|nested] 3+ messages in thread