mlxsw: spectrum_acl_tcam: Move devlink param to TCAM code

Cited commit added 'DEVLINK_CMD_PARAM_DEL' notifications whenever the
network namespace of the devlink instance is changed. Specifically, the
notifications are generated after calling reload_down(), but before
calling reload_up(). At this stage, the data structures accessed while
reading the value of the "acl_region_rehash_interval" devlink parameter
are uninitialized, resulting in a use-after-free [1].

Fix by moving the registration and unregistration of the devlink
parameter to the TCAM code where it is actually used. This means that
the parameter is unregistered during reload_down() and then
re-registered during reload_up(), avoiding the use-after-free between
these two operations.

Reproducer:

 # ip netns add test123
 # devlink dev reload pci/0000:06:00.0 netns test123

[1]
BUG: KASAN: use-after-free in mlxsw_sp_acl_tcam_vregion_rehash_intrvl_get+0xb2/0xd0
Read of size 4 at addr ffff888162fd37d8 by task devlink/1323
[...]
Call Trace:
 <TASK>
 dump_stack_lvl+0x95/0xbd
 print_report+0x181/0x4a1
 kasan_report+0xdb/0x200
 mlxsw_sp_acl_tcam_vregion_rehash_intrvl_get+0xb2/0xd0
 mlxsw_sp_params_acl_region_rehash_intrvl_get+0x32/0x80
 devlink_nl_param_fill.constprop.0+0x29a/0x11e0
 devlink_param_notify.constprop.0+0xb9/0x250
 devlink_notify_unregister+0xbc/0x470
 devlink_reload+0x1aa/0x440
 devlink_nl_cmd_reload+0x559/0x11b0
 genl_family_rcv_msg_doit.isra.0+0x1f8/0x2e0
 genl_rcv_msg+0x558/0x7f0
 netlink_rcv_skb+0x170/0x440
 genl_rcv+0x2d/0x40
 netlink_unicast+0x53f/0x810
 netlink_sendmsg+0x961/0xe80
 __sys_sendto+0x2a4/0x420
 __x64_sys_sendto+0xe5/0x1c0
 do_syscall_64+0x38/0x80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 7d7e9169a3ec ("devlink: move devlink reload notifications back in between _down() and _up() calls")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 0 insertions, 52 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index b150e97b97b7..a8f94b7544ee 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -3861,52 +3861,6 @@ static int mlxsw_sp_kvd_sizes_get(struct mlxsw_core *mlxsw_core,
 	return 0;
 }
 
-static int
-mlxsw_sp_params_acl_region_rehash_intrvl_get(struct devlink *devlink, u32 id,
-					     struct devlink_param_gset_ctx *ctx)
-{
-	struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
-	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
-
-	ctx->val.vu32 = mlxsw_sp_acl_region_rehash_intrvl_get(mlxsw_sp);
-	return 0;
-}
-
-static int
-mlxsw_sp_params_acl_region_rehash_intrvl_set(struct devlink *devlink, u32 id,
-					     struct devlink_param_gset_ctx *ctx)
-{
-	struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
-	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
-
-	return mlxsw_sp_acl_region_rehash_intrvl_set(mlxsw_sp, ctx->val.vu32);
-}
-
-static const struct devlink_param mlxsw_sp2_devlink_params[] = {
-	DEVLINK_PARAM_DRIVER(MLXSW_DEVLINK_PARAM_ID_ACL_REGION_REHASH_INTERVAL,
-			     "acl_region_rehash_interval",
-			     DEVLINK_PARAM_TYPE_U32,
-			     BIT(DEVLINK_PARAM_CMODE_RUNTIME),
-			     mlxsw_sp_params_acl_region_rehash_intrvl_get,
-			     mlxsw_sp_params_acl_region_rehash_intrvl_set,
-			     NULL),
-};
-
-static int mlxsw_sp2_params_register(struct mlxsw_core *mlxsw_core)
-{
-	struct devlink *devlink = priv_to_devlink(mlxsw_core);
-
-	return devl_params_register(devlink, mlxsw_sp2_devlink_params,
-				    ARRAY_SIZE(mlxsw_sp2_devlink_params));
-}
-
-static void mlxsw_sp2_params_unregister(struct mlxsw_core *mlxsw_core)
-{
-	devl_params_unregister(priv_to_devlink(mlxsw_core),
-			       mlxsw_sp2_devlink_params,
-			       ARRAY_SIZE(mlxsw_sp2_devlink_params));
-}
-
 static void mlxsw_sp_ptp_transmitted(struct mlxsw_core *mlxsw_core,
 				     struct sk_buff *skb, u16 local_port)
 {
@@ -3984,8 +3938,6 @@ static struct mlxsw_driver mlxsw_sp2_driver = {
 	.trap_policer_counter_get	= mlxsw_sp_trap_policer_counter_get,
 	.txhdr_construct		= mlxsw_sp_txhdr_construct,
 	.resources_register		= mlxsw_sp2_resources_register,
-	.params_register		= mlxsw_sp2_params_register,
-	.params_unregister		= mlxsw_sp2_params_unregister,
 	.ptp_transmitted		= mlxsw_sp_ptp_transmitted,
 	.txhdr_len			= MLXSW_TXHDR_LEN,
 	.profile			= &mlxsw_sp2_config_profile,
@@ -4023,8 +3975,6 @@ static struct mlxsw_driver mlxsw_sp3_driver = {
 	.trap_policer_counter_get	= mlxsw_sp_trap_policer_counter_get,
 	.txhdr_construct		= mlxsw_sp_txhdr_construct,
 	.resources_register		= mlxsw_sp2_resources_register,
-	.params_register		= mlxsw_sp2_params_register,
-	.params_unregister		= mlxsw_sp2_params_unregister,
 	.ptp_transmitted		= mlxsw_sp_ptp_transmitted,
 	.txhdr_len			= MLXSW_TXHDR_LEN,
 	.profile			= &mlxsw_sp2_config_profile,
@@ -4060,8 +4010,6 @@ static struct mlxsw_driver mlxsw_sp4_driver = {
 	.trap_policer_counter_get	= mlxsw_sp_trap_policer_counter_get,
 	.txhdr_construct		= mlxsw_sp_txhdr_construct,
 	.resources_register		= mlxsw_sp2_resources_register,
-	.params_register		= mlxsw_sp2_params_register,
-	.params_unregister		= mlxsw_sp2_params_unregister,
 	.ptp_transmitted		= mlxsw_sp_ptp_transmitted,
 	.txhdr_len			= MLXSW_TXHDR_LEN,
 	.profile			= &mlxsw_sp4_config_profile,