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From: Edward Cree <ecree@solarflare.com>
To: <linux-net-drivers@solarflare.com>, <davem@davemloft.net>
Cc: <netdev@vger.kernel.org>
Subject: [PATCH net 3/4] sfc: null out channel->rps_flow_id after freeing it
Date: Tue, 18 Aug 2020 13:44:18 +0100	[thread overview]
Message-ID: <ea34ed03-23e8-568f-ec50-1f238bc0a350@solarflare.com> (raw)
In-Reply-To: <d8d6cdfc-7d4f-81ec-8b3e-bc207a2c7d50@solarflare.com>

If an ef100_net_open() fails, ef100_net_stop() may be called without
 channel->rps_flow_id having been written; thus it may hold the address
 freed by a previous ef100_net_stop()'s call to efx_remove_filters().
 This then causes a double-free when efx_remove_filters() is called
 again, leading to a panic.
To prevent this, after freeing it, overwrite it with NULL.

Fixes: a9dc3d5612ce ("sfc_ef100: RX filter table management and related gubbins")
Signed-off-by: Edward Cree <ecree@solarflare.com>
---
 drivers/net/ethernet/sfc/rx_common.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/sfc/rx_common.c b/drivers/net/ethernet/sfc/rx_common.c
index ef9bca92b0b7..5e29284c89c9 100644
--- a/drivers/net/ethernet/sfc/rx_common.c
+++ b/drivers/net/ethernet/sfc/rx_common.c
@@ -849,6 +849,7 @@ void efx_remove_filters(struct efx_nic *efx)
 	efx_for_each_channel(channel, efx) {
 		cancel_delayed_work_sync(&channel->filter_work);
 		kfree(channel->rps_flow_id);
+		channel->rps_flow_id = NULL;
 	}
 #endif
 	down_write(&efx->filter_sem);


  parent reply	other threads:[~2020-08-18 12:44 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-18 12:41 [PATCH net 0/4] sfc: more EF100 fixes Edward Cree
2020-08-18 12:43 ` [PATCH net 1/4] sfc: really check hash is valid before using it Edward Cree
2020-08-18 18:54   ` Jesse Brandeburg
2020-08-18 12:43 ` [PATCH net 2/4] sfc: take correct lock in ef100_reset() Edward Cree
2020-08-18 18:55   ` Jesse Brandeburg
2020-08-18 12:44 ` Edward Cree [this message]
2020-08-18 18:58   ` [PATCH net 3/4] sfc: null out channel->rps_flow_id after freeing it Jesse Brandeburg
2020-08-18 19:01     ` Jesse Brandeburg
2020-08-18 12:44 ` [PATCH net 4/4] sfc: don't free_irq()s if they were never requested Edward Cree
2020-08-18 19:03   ` Jesse Brandeburg
2020-08-18 19:49 ` [PATCH net 0/4] sfc: more EF100 fixes David Miller

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