Re: [PATCH net-next] net: airoha: Validate egress gdm port in airoha_ppe_foe_entry_prepare()

Michal Kubiak
2025-03-12T15:53:13Z

On Wed, Mar 12, 2025 at 03:54:21PM +0100, Lorenzo Bianconi wrote:
> > On Wed, Mar 12, 2025 at 12:31:46PM +0100, Lorenzo Bianconi wrote:
> > > The system occasionally crashes dereferencing a NULL pointer when it is
> > > forwarding constant, high load bidirectional traffic.
> > >
> > > [ 2149.913414] Unable to handle kernel read from unreadable memory at virtual address 0000000000000000
> > > [ 2149.925812] Mem abort info:
> > > [ 2149.928713] ESR = 0x0000000096000005
> > > [ 2149.932762] EC = 0x25: DABT (current EL), IL = 32 bits
> > > [ 2149.938429] SET = 0, FnV = 0
> > > [ 2149.941814] EA = 0, S1PTW = 0
> > > [ 2149.945187] FSC = 0x05: level 1 translation fault
> > > [ 2149.950348] Data abort info:
> > > [ 2149.953472] ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
> > > [ 2149.959243] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
> > > [ 2149.964593] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> > > [ 2149.970243] user pgtable: 4k pages, 39-bit VAs, pgdp=000000008b507000
> > > [ 2149.977068] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
> > > [ 2149.986062] Internal error: Oops: 0000000096000005 [#1] SMP
> > > [ 2150.082282] arht_wrapper(O) i2c_core arht_hook(O) crc32_generic
> > > [ 2150.177623] CPU: 0 PID: 38 Comm: kworker/u9:1 Tainted: G O 6.6.73 #0
> > > [ 2150.185362] Hardware name: Airoha AN7581 Evaluation Board (DT)
> > > [ 2150.191189] Workqueue: nf_ft_offload_add nf_flow_rule_route_ipv6 [nf_flow_table]
> > > [ 2150.198653] pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> > > [ 2150.205615] pc : airoha_ppe_flow_offload_replace.isra.0+0x6dc/0xc54
> > > [ 2150.211882] lr : airoha_ppe_flow_offload_replace.isra.0+0x6cc/0xc54
> > > [ 2150.218149] sp : ffffffc080e8ba10
> > > [ 2150.221456] x29: ffffffc080e8bae0 x28: ffffff80080b0000 x27: 0000000000000000
> > > [ 2150.228591] x26: ffffff8001c70020 x25: 0000000000000002 x24: 0000000000000000
> > > [ 2150.235727] x23: 0000000061000000 x22: 00000000ffffffed x21: ffffffc080e8bbb0
> > > [ 2150.242862] x20: ffffff8001c70000 x19: 0000000000000008 x18: 0000000000000000
> > > [ 2150.249998] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
> > > [ 2150.257133] x14: 0000000000000001 x13: 0000000000000008 x12: 0101010101010101
> > > [ 2150.264268] x11: 7f7f7f7f7f7f7f7f x10: 0000000000000041 x9 : 0000000000000000
> > > [ 2150.271404] x8 : ffffffc080e8bad8 x7 : 0000000000000000 x6 : 0000000000000015
> > > [ 2150.278540] x5 : ffffffc080e8ba4e x4 : 0000000000000004 x3 : 0000000000000000
> > > [ 2150.285675] x2 : 0000000000000008 x1 : 00000000080b0000 x0 : 0000000000000000
> > > [ 2150.292811] Call trace:
> > > [ 2150.295250] airoha_ppe_flow_offload_replace.isra.0+0x6dc/0xc54
> > > [ 2150.301171] airoha_ppe_setup_tc_block_cb+0x7c/0x8b4
> > > [ 2150.306135] nf_flow_offload_ip_hook+0x710/0x874 [nf_flow_table]
> > > [ 2150.312168] nf_flow_rule_route_ipv6+0x53c/0x580 [nf_flow_table]
> > > [ 2150.318200] process_one_work+0x178/0x2f0
> > > [ 2150.322211] worker_thread+0x2e4/0x4cc
> > > [ 2150.325953] kthread+0xd8/0xdc
> > > [ 2150.329008] ret_from_fork+0x10/0x20
> > > [ 2150.332589] Code: b9007bf7 b4001e9c f9448380 b9491381 (f9400000)
> > > [ 2150.338681] ---[ end trace 0000000000000000 ]---
> > > [ 2150.343298] Kernel panic - not syncing: Oops: Fatal exception
> > > [ 2150.349035] SMP: stopping secondary CPUs
> > > [ 2150.352954] Kernel Offset: disabled
> > > [ 2150.356438] CPU features: 0x0,00000000,00000000,1000400b
> > > [ 2150.361743] Memory Limit: none
> > >
> > > Fix the issue validating egress gdm port in airoha_ppe_foe_entry_prepare
> > > routine.
> > >
> > > Fixes: 00a7678310fe ("net: airoha: Introduce flowtable offload support")
> >
> > The patch has "Fixes" tag, but it is sent to "net-next" tree.
> > I think it's rather a candidate for "net".
>
> The offending commit is just in net-next at the moment. Do you prefer to drop
> the Fixes tag?

Oh, I didn't realize this is a new driver in net-next. So, I'm OK with
the "Fixes" tag then.

>
> >
> > > Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> > > ---
> > > drivers/net/ethernet/airoha/airoha_eth.c | 16 ++++++++++++++++
> > > drivers/net/ethernet/airoha/airoha_eth.h | 3 +++
> > > drivers/net/ethernet/airoha/airoha_ppe.c | 10 ++++++++--
> > > 3 files changed, 27 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
> > > index c0a642568ac115ea9df6fbaf7133627a4405a36c..776222595b84e4fba6ae5943420e0edf0d0ecf8f 100644
> > > --- a/drivers/net/ethernet/airoha/airoha_eth.c
> > > +++ b/drivers/net/ethernet/airoha/airoha_eth.c
> > > @@ -2454,6 +2454,22 @@ static void airoha_metadata_dst_free(struct airoha_gdm_port *port)
> > > }
> > > }
> > >
> > > +int airoha_is_valid_gdm_port(struct airoha_eth *eth,
> > > + struct airoha_gdm_port *port)
> > > +{
> > > + int i;
> > > +
> > > + for (i = 0; i < ARRAY_SIZE(eth->ports); i++) {
> >
> > You could reduce the number of lines by moving the declaration inside the
> > loop:
> > for (int i = 0; i < ARRAY_SIZE(eth->ports); i++) {
>
> to be consistent with the driver I prefer to keep the current approach.

OK. That was my suggestion only. Let's keep the code consistent then.

>
> >
> > > + if (!eth->ports[i])
> > > + continue;
> >
> > Isn't this NULL check redundant?
> > In the second check you compare the table element to a real pointer.
>
> Can netdev_priv() be NULL? If not, I guess we can remove this check.

I guess it shouldn't be NULL since "devm_alloc_etherdev_mqs()" was
called, but I'm not 100% sure if there are any special cases for the "airoha"
driver. Maybe in such cases it would be better to check for the netdev_priv?
Anyway, such checks seem a bit too defensive to me.

Thanks,
Michal

>
> Regards,
> Lorenzo
>
> >
> > > +
> > > + if (eth->ports[i] == port)
> > > + return 0;
> > > + }
> > > +
> > > + return -EINVAL;
> > > +}
> > > +
> > > static int airoha_alloc_gdm_port(struct airoha_eth *eth,
> > > struct device_node *np, int index)
> > > {
> > > diff --git a/drivers/net/ethernet/airoha/airoha_eth.h b/drivers/net/ethernet/airoha/airoha_eth.h
> > > index f66b9b736b9447b31afc036eb906d0a1c617e132..c7d4f124d11481cd31c1566936cd47e3446877c0 100644
> > > --- a/drivers/net/ethernet/airoha/airoha_eth.h
> > > +++ b/drivers/net/ethernet/airoha/airoha_eth.h
> > > @@ -532,6 +532,9 @@ u32 airoha_rmw(void __iomem *base, u32 offset, u32 mask, u32 val);
> > > #define airoha_qdma_clear(qdma, offset, val) \
> > > airoha_rmw((qdma)->regs, (offset), (val), 0)
> > >
> > > +int airoha_is_valid_gdm_port(struct airoha_eth *eth,
> > > + struct airoha_gdm_port *port);
> > > +
> > > void airoha_ppe_check_skb(struct airoha_ppe *ppe, u16 hash);
> > > int airoha_ppe_setup_tc_block_cb(enum tc_setup_type type, void *type_data,
> > > void *cb_priv);
> > > diff --git a/drivers/net/ethernet/airoha/airoha_ppe.c b/drivers/net/ethernet/airoha/airoha_ppe.c
> > > index 8b55e871352d359fa692c253d3f3315c619472b3..65833e2058194a64569eafec08b80df8190bba6c 100644
> > > --- a/drivers/net/ethernet/airoha/airoha_ppe.c
> > > +++ b/drivers/net/ethernet/airoha/airoha_ppe.c
> > > @@ -197,7 +197,8 @@ static int airoha_get_dsa_port(struct net_device **dev)
> > > #endif
> > > }
> > >
> > > -static int airoha_ppe_foe_entry_prepare(struct airoha_foe_entry *hwe,
> > > +static int airoha_ppe_foe_entry_prepare(struct airoha_eth *eth,
> > > + struct airoha_foe_entry *hwe,
> > > struct net_device *dev, int type,
> > > struct airoha_flow_data *data,
> > > int l4proto)
> > > @@ -224,6 +225,11 @@ static int airoha_ppe_foe_entry_prepare(struct airoha_foe_entry *hwe,
> > > if (dev) {
> > > struct airoha_gdm_port *port = netdev_priv(dev);
> > > u8 pse_port;
> > > + int err;
> > > +
> > > + err = airoha_is_valid_gdm_port(eth, port);
> > > + if (err)
> > > + return err;
> > >
> > > if (dsa_port >= 0)
> > > pse_port = port->id == 4 ? FE_PSE_PORT_GDM4 : port->id;
> > > @@ -633,7 +639,7 @@ static int airoha_ppe_flow_offload_replace(struct airoha_gdm_port *port,
> > > !is_valid_ether_addr(data.eth.h_dest))
> > > return -EINVAL;
> > >
> > > - err = airoha_ppe_foe_entry_prepare(&hwe, odev, offload_type,
> > > + err = airoha_ppe_foe_entry_prepare(eth, &hwe, odev, offload_type,
> > > &data, l4proto);
> > > if (err)
> > > return err;
> > >
> > > ---
> > > base-commit: 0ea09cbf8350b70ad44d67a1dcb379008a356034
> > > change-id: 20250312-airoha-flowtable-null-ptr-fix-a4656d12546a
> > >
> > > Best regards,
> > > --
> > > Lorenzo Bianconi <lorenzo@kernel.org>
> > >
> > >