From: Amit Cohen <amcohen@nvidia.com> stable inclusion from stable-v5.10.83 commit 90d0736876c50ecde1a3275636a06b9ddb1cace9 bugzilla: 185879 https://gitee.com/openeuler/kernel/issues/I4QUVG Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 63b08b1f6834bbb0b4f7783bf63b80c8c8e9a047 ] When processing port up/down events generated by the device's firmware, the driver protects itself from events reported for non-existent local ports, but not the CPU port (local port 0), which exists, but lacks a netdev. This can result in a NULL pointer dereference when calling netif_carrier_{on,off}(). Fix this by bailing early when processing an event reported for the CPU port. Problem was only observed when running on top of a buggy emulator. Fixes: 28b1987ef506 ("mlxsw: spectrum: Register CPU port with devlink") Signed-off-by: Amit Cohen <amcohen@nvidia.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Chen Jun <chenjun102@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- drivers/net/ethernet/mellanox/mlxsw/spectrum.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c index 1a9978f501ba..4110e15c22c7 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c @@ -2058,7 +2058,7 @@ static void mlxsw_sp_pude_event_func(const struct mlxsw_reg_info *reg, max_ports = mlxsw_core_max_ports(mlxsw_sp->core); local_port = mlxsw_reg_pude_local_port_get(pude_pl); - if (WARN_ON_ONCE(local_port >= max_ports)) + if (WARN_ON_ONCE(!local_port || local_port >= max_ports)) return; mlxsw_sp_port = mlxsw_sp->ports[local_port]; if (!mlxsw_sp_port) -- 2.20.1