Subject: [PATCH 03/36] bnxt_en: Fix NULL ptr dereference crash in bnxt_fw_reset_task()

From: Vasundhara Volam <[email-masked]>
Date: Sat, 5 Sep 2020 22:55:37 -0400

[ Upstream commit b16939b59cc00231a75d224fd058d22c9d064976 ]

bnxt_fw_reset_task() which runs from a workqueue can race with
bnxt_remove_one().  For example, if firmware reset and VF FLR are
happening at about the same time.

bnxt_remove_one() already cancels the workqueue and waits for it
to finish, but we need to do this earlier before the devlink
reporters are destroyed.  This will guarantee that
the devlink reporters will always be valid when bnxt_fw_reset_task()
is still running.

Fixes: b148bb238c02 ("bnxt_en: Fix possible crash in bnxt_fw_reset_task().")
Reviewed-by: Edwin Peer <[email-masked]>
Signed-off-by: Vasundhara Volam <[email-masked]>
Signed-off-by: Michael Chan <[email-masked]>
Signed-off-by: Jakub Kicinski <[email-masked]>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 00a2137c2b31..59257ee25168 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -11385,14 +11385,15 @@ static void bnxt_remove_one(struct pci_dev *pdev)
 	if (BNXT_PF(bp))
 		bnxt_sriov_disable(bp);
 
+	clear_bit(BNXT_STATE_IN_FW_RESET, &bp->state);
+	bnxt_cancel_sp_work(bp);
+	bp->sp_event = 0;
+
 	bnxt_dl_fw_reporters_destroy(bp, true);
 	pci_disable_pcie_error_reporting(pdev);
 	unregister_netdev(dev);
 	bnxt_dl_unregister(bp);
 	bnxt_shutdown_tc(bp);
-	clear_bit(BNXT_STATE_IN_FW_RESET, &bp->state);
-	bnxt_cancel_sp_work(bp);
-	bp->sp_event = 0;
 
 	bnxt_clear_int_mode(bp);
 	bnxt_hwrm_func_drv_unrgtr(bp);
-- 
2.26.2