kernel/linux.git/net/dsa/slave.c, branch v6.1.168

net: dsa: fix netdev_priv() dereference before check on non-DSA netdevice events

2025-02-21T12:50:11+00:00

commit 844f104790bd69c2e4dbb9ee3eba46fde1fcea7b upstream. After the blamed commit, we started doing this dereference for every NETDEV_CHANGEUPPER and NETDEV_PRECHANGEUPPER event in the system. static inline struct dsa_port *dsa_user_to_port(const struct net_device *dev) { struct dsa_user_priv *p = netdev_priv(dev); return p->dp; } Which is obviously bogus, because not all net_devices have a netdev_priv() of type struct dsa_user_priv. But struct dsa_user_priv is fairly small, and p->dp means dereferencing 8 bytes starting with offset 16. Most drivers allocate that much private memory anyway, making our access not fault, and we discard the bogus data quickly afterwards, so this wasn't caught. But the dummy interface is somewhat special in that it calls alloc_netdev() with a priv size of 0. So every netdev_priv() dereference is invalid, and we get this when we emit a NETDEV_PRECHANGEUPPER event with a VLAN as its new upper: $ ip link add dummy1 type dummy $ ip link add link dummy1 name dummy1.100 type vlan id 100 [ 43.309174] ================================================================== [ 43.316456] BUG: KASAN: slab-out-of-bounds in dsa_user_prechangeupper+0x30/0xe8 [ 43.323835] Read of size 8 at addr ffff3f86481d2990 by task ip/374 [ 43.330058] [ 43.342436] Call trace: [ 43.366542] dsa_user_prechangeupper+0x30/0xe8 [ 43.371024] dsa_user_netdevice_event+0xb38/0xee8 [ 43.375768] notifier_call_chain+0xa4/0x210 [ 43.379985] raw_notifier_call_chain+0x24/0x38 [ 43.384464] __netdev_upper_dev_link+0x3ec/0x5d8 [ 43.389120] netdev_upper_dev_link+0x70/0xa8 [ 43.393424] register_vlan_dev+0x1bc/0x310 [ 43.397554] vlan_newlink+0x210/0x248 [ 43.401247] rtnl_newlink+0x9fc/0xe30 [ 43.404942] rtnetlink_rcv_msg+0x378/0x580 Avoid the kernel oops by dereferencing after the type check, as customary. Fixes: 4c3f80d22b2e ("net: dsa: walk through all changeupper notifier functions") Reported-and-tested-by: syzbot+d81bcd883824180500c8@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/0000000000001d4255060e87545c@google.com/ Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20240110003354.2796778-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski Signed-off-by: Wenshan Lan Signed-off-by: Greg Kroah-Hartman

net: dsa: don't error out when drivers return ETH_DATA_LEN in .port_max_mtu()

2023-03-22T12:33:49+00:00

[ Upstream commit 636e8adf7878eab3614250234341bde45537f47a ] Currently, when dsa_slave_change_mtu() is called on a user port where dev->max_mtu is 1500 (as returned by ds->ops->port_max_mtu()), the code will stumble upon this check: if (new_master_mtu > mtu_limit) return -ERANGE; because new_master_mtu is adjusted for the tagger overhead but mtu_limit is not. But it would be good if the logic went through, for example if the DSA master really depends on an MTU adjustment to accept DSA-tagged frames. To make the code pass through the check, we need to adjust mtu_limit for the overhead as well, if the minimum restriction was caused by the DSA user port's MTU (dev->max_mtu). A DSA user port MTU and a DSA master MTU are always offset by the protocol overhead. Currently no drivers return 1500 .port_max_mtu(), but this is only temporary and a bug in itself - mv88e6xxx should have done that, but since commit b9c587fed61c ("dsa: mv88e6xxx: Include tagger overhead when setting MTU for DSA and CPU ports") it no longer does. This is a preparation for fixing that. Fixes: bfcb813203e6 ("net: dsa: configure the MTU for switch ports") Signed-off-by: Vladimir Oltean Reviewed-by: Simon Horman Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: dsa: uninitialized variable in dsa_slave_netdevice_event()

2022-10-15T10:15:27+00:00

Return zero if both dsa_slave_dev_check() and netdev_uses_dsa() are false. Fixes: acc43b7bf52a ("net: dsa: allow masters to join a LAG") Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller

net: dsa: don't leave dangling pointers in dp->pl when failing

2022-10-01T01:17:16+00:00

There is a desire to simplify the dsa_port registration path with devlink, and this involves reworking a bit how user ports which fail to connect to their PHY (because it's missing) get reinitialized as UNUSED devlink ports. The desire is for the change to look something like this; basically dsa_port_setup() has failed, we just change dp->type and call dsa_port_setup() again. -/* Destroy the current devlink port, and create a new one which has the UNUSED - * flavour. - */ -static int dsa_port_reinit_as_unused(struct dsa_port *dp) +static int dsa_port_setup_as_unused(struct dsa_port *dp) { - dsa_port_devlink_teardown(dp); dp->type = DSA_PORT_TYPE_UNUSED; - return dsa_port_devlink_setup(dp); + return dsa_port_setup(dp); } For an UNUSED port, dsa_port_setup() mostly only calls dsa_port_devlink_setup() anyway, so we could get away with calling just that. But if we call the full blown dsa_port_setup(dp) (which will be needed to properly set dp->setup = true), the callee will have the tendency to go through this code block too, and call dsa_port_disable(dp): switch (dp->type) { case DSA_PORT_TYPE_UNUSED: dsa_port_disable(dp); break; That is not very good, because dsa_port_disable() has this hidden inside of it: if (dp->pl) phylink_stop(dp->pl); Fact is, we are not prepared to handle a call to dsa_port_disable() with a struct dsa_port that came from a previous (and failed) call to dsa_port_setup(). We do not clean up dp->pl, and this will make the second call to dsa_port_setup() call phylink_stop() on a dangling dp->pl pointer. Solve this by creating an API for phylink destruction which is symmetric to the phylink creation, and never leave dp->pl set to anything except NULL or a valid phylink structure. Signed-off-by: Vladimir Oltean Signed-off-by: Jiri Pirko Signed-off-by: Jakub Kicinski

net: dsa: allow masters to join a LAG

2022-09-20T08:32:36+00:00

There are 2 ways in which a DSA user port may become handled by 2 CPU ports in a LAG: (1) its current DSA master joins a LAG ip link del bond0 && ip link add bond0 type bond mode 802.3ad ip link set eno2 master bond0 When this happens, all user ports with "eno2" as DSA master get automatically migrated to "bond0" as DSA master. (2) it is explicitly configured as such by the user # Before, the DSA master was eno3 ip link set swp0 type dsa master bond0 The design of this configuration is that the LAG device dynamically becomes a DSA master through dsa_master_setup() when the first physical DSA master becomes a LAG slave, and stops being so through dsa_master_teardown() when the last physical DSA master leaves. A LAG interface is considered as a valid DSA master only if it contains existing DSA masters, and no other lower interfaces. Therefore, we mainly rely on method (1) to enter this configuration. Each physical DSA master (LAG slave) retains its dev->dsa_ptr for when it becomes a standalone DSA master again. But the LAG master also has a dev->dsa_ptr, and this is actually duplicated from one of the physical LAG slaves, and therefore needs to be balanced when LAG slaves come and go. To the switch driver, putting DSA masters in a LAG is seen as putting their associated CPU ports in a LAG. We need to prepare cross-chip host FDB notifiers for CPU ports in a LAG, by calling the driver's ->lag_fdb_add method rather than ->port_fdb_add. Signed-off-by: Vladimir Oltean Signed-off-by: Paolo Abeni

net: dsa: allow the DSA master to be seen and changed through rtnetlink

2022-09-20T08:32:35+00:00

Some DSA switches have multiple CPU ports, which can be used to improve CPU termination throughput, but DSA, through dsa_tree_setup_cpu_ports(), sets up only the first one, leading to suboptimal use of hardware. The desire is to not change the default configuration but to permit the user to create a dynamic mapping between individual user ports and the CPU port that they are served by, configurable through rtnetlink. It is also intended to permit load balancing between CPU ports, and in that case, the foreseen model is for the DSA master to be a bonding interface whose lowers are the physical DSA masters. To that end, we create a struct rtnl_link_ops for DSA user ports with the "dsa" kind. We expose the IFLA_DSA_MASTER link attribute that contains the ifindex of the newly desired DSA master. Signed-off-by: Vladimir Oltean Signed-off-by: Paolo Abeni

net: dsa: introduce dsa_port_get_master()

2022-09-20T08:32:35+00:00

There is a desire to support for DSA masters in a LAG. That configuration is intended to work by simply enslaving the master to a bonding/team device. But the physical DSA master (the LAG slave) still has a dev->dsa_ptr, and that cpu_dp still corresponds to the physical CPU port. However, we would like to be able to retrieve the LAG that's the upper of the physical DSA master. In preparation for that, introduce a helper called dsa_port_get_master() that replaces all occurrences of the dp->cpu_dp->master pattern. The distinction between LAG and non-LAG will be made later within the helper itself. Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: Paolo Abeni

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2022-08-25T23:07:42+00:00

drivers/net/ethernet/mellanox/mlx5/core/en_fs.c 21234e3a84c7 ("net/mlx5e: Fix use after free in mlx5e_fs_init()") c7eafc5ed068 ("net/mlx5e: Convert ethtool_steering member of flow_steering struct to pointer") https://lore.kernel.org/all/20220825104410.67d4709c@canb.auug.org.au/ https://lore.kernel.org/all/20220823055533.334471-1-saeed@kernel.org/ Signed-off-by: Jakub Kicinski

net: dsa: don't dereference NULL extack in dsa_slave_changeupper()

2022-08-23T14:54:16+00:00

When a driver returns -EOPNOTSUPP in dsa_port_bridge_join() but failed to provide a reason for it, DSA attempts to set the extack to say that software fallback will kick in. The problem is, when we use brctl and the legacy bridge ioctls, the extack will be NULL, and DSA dereferences it in the process of setting it. Sergei Antonov proves this using the following stack trace: Unable to handle kernel NULL pointer dereference at virtual address 00000000 PC is at dsa_slave_changeupper+0x5c/0x158 dsa_slave_changeupper from raw_notifier_call_chain+0x38/0x6c raw_notifier_call_chain from __netdev_upper_dev_link+0x198/0x3b4 __netdev_upper_dev_link from netdev_master_upper_dev_link+0x50/0x78 netdev_master_upper_dev_link from br_add_if+0x430/0x7f4 br_add_if from br_ioctl_stub+0x170/0x530 br_ioctl_stub from br_ioctl_call+0x54/0x7c br_ioctl_call from dev_ifsioc+0x4e0/0x6bc dev_ifsioc from dev_ioctl+0x2f8/0x758 dev_ioctl from sock_ioctl+0x5f0/0x674 sock_ioctl from sys_ioctl+0x518/0xe40 sys_ioctl from ret_fast_syscall+0x0/0x1c Fix the problem by only overriding the extack if non-NULL. Fixes: 1c6e8088d9a7 ("net: dsa: allow port_bridge_join() to override extack message") Link: https://lore.kernel.org/netdev/CABikg9wx7vB5eRDAYtvAm7fprJ09Ta27a4ZazC=NX5K4wn6pWA@mail.gmail.com/ Reported-by: Sergei Antonov Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Tested-by: Sergei Antonov Link: https://lore.kernel.org/r/20220819173925.3581871-1-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski

net: dsa: only bring down user ports assigned to a given DSA master

2022-08-23T09:39:22+00:00

This is an adaptation of commit c0a8a9c27493 ("net: dsa: automatically bring user ports down when master goes down") for multiple DSA masters. When a DSA master goes down, only the user ports under its control should go down too, the others can still send/receive traffic. Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: Paolo Abeni