Commit 15faa1f67ab4 ("lan966x: Fix crash when adding interface under a lag") fixed a similar issue in the lan966x driver caused by a NULL pointer dereference. The ocelot_set_aggr_pgids() function in the ocelot driver has similar logic and is susceptible to the same crash. This issue specifically affects the ocelot_vsc7514.c frontend, which leaves unused ports as NULL pointers. The felix_vsc9959.c frontend is unaffected as it uses the DSA framework which registers all ports. Fix this by checking if the port pointer is valid before accessing it. Fixes: 528d3f190c98 ("net: mscc: ocelot: drop the use of the "lags" array") Signed-off-by: Jerry Wu --- v3: - Resending the correct version that compiles properly. - Retained the 'bond' variable as confirmed necessary in discussion with Vladimir Oltean. - Added links to previous versions as requested. - Thanks to the reviewers for the gentle and detailed feedback and guidance. v2: https://lore.kernel.org/netdev/20251220210808.325isrbvmhjp3tlg@skbuf/T/ - Addressed comments from v1 regarding variable name and null checking. - Sent by accident as a draft. v1: https://lore.kernel.org/lkml/20251220180113.724txltmrkxzyaql@skbuf/T/ - Try to fix the crash in the same way as previous patch did but failed for - improper variable name that is shadowing the "int port" definition. - unnecessary and incorrect hunk for null checking. - improper commit commit title. drivers/net/ethernet/mscc/ocelot.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c index 08bee56aea35..c345d9b17c89 100644 --- a/drivers/net/ethernet/mscc/ocelot.c +++ b/drivers/net/ethernet/mscc/ocelot.c @@ -2307,14 +2307,16 @@ static void ocelot_set_aggr_pgids(struct ocelot *ocelot) /* Now, set PGIDs for each active LAG */ for (lag = 0; lag < ocelot->num_phys_ports; lag++) { - struct net_device *bond = ocelot->ports[lag]->bond; + struct ocelot_port *ocelot_port = ocelot->ports[lag]; int num_active_ports = 0; + struct net_device *bond; unsigned long bond_mask; u8 aggr_idx[16]; - if (!bond || (visited & BIT(lag))) + if (!ocelot_port || !ocelot_port->bond || (visited & BIT(lag))) continue; + bond = ocelot_port->bond; bond_mask = ocelot_get_bond_mask(ocelot, bond); for_each_set_bit(port, &bond_mask, ocelot->num_phys_ports) { -- 2.52.0