Commit d8c40b9d authored Aug 23, 2024 by Larysa Zaremba Committed by Tony Nguyen Sep 03, 2024

ice: check ICE_VSI_DOWN under rtnl_lock when preparing for reset



Consider the following scenario:

.ndo_bpf()		| ice_prepare_for_reset()		|
________________________|_______________________________________|
rtnl_lock()		|					|
ice_down()		|					|
			| test_bit(ICE_VSI_DOWN) - true		|
			| ice_dis_vsi() returns			|
ice_up()		|					|
			| proceeds to rebuild a running VSI	|

.ndo_bpf() is not the only rtnl-locked callback that toggles the interface
to apply new configuration. Another example is .set_channels().

To avoid the race condition above, act only after reading ICE_VSI_DOWN
under rtnl_lock.

Fixes: 0f9d5027 ("ice: Refactor VSI allocation, deletion and rebuild flow")
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Chandan Kumar Rout <chandanx.rout@intel.com>
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

parent f50c6876

drivers/net/ethernet/intel/ice/ice_lib.c

+6 −6

Original line number	Diff line number	Diff line
		@@ -2672,8 +2672,7 @@ int ice_ena_vsi(struct ice_vsi *vsi, bool locked)
		*/
		void ice_dis_vsi(struct ice_vsi *vsi, bool locked)
		{
		if (test_bit(ICE_VSI_DOWN, vsi->state))
		return;
		bool already_down = test_bit(ICE_VSI_DOWN, vsi->state);

		set_bit(ICE_VSI_NEEDS_RESTART, vsi->state);

		@@ -2681,15 +2680,16 @@ void ice_dis_vsi(struct ice_vsi *vsi, bool locked)
		if (netif_running(vsi->netdev)) {
		if (!locked)
		rtnl_lock();

		already_down = test_bit(ICE_VSI_DOWN, vsi->state);
		if (!already_down)
		ice_vsi_close(vsi);

		if (!locked)
		rtnl_unlock();
		} else {
		} else if (!already_down) {
		ice_vsi_close(vsi);
		}
		} else if (vsi->type == ICE_VSI_CTRL) {
		} else if (vsi->type == ICE_VSI_CTRL && !already_down) {
		ice_vsi_close(vsi);
		}
		}