From: Vinicius Costa Gomes <vinicius.gomes@xxxxxxxxx>
[ Upstream commit 7b292608db23ccbbfbfa50cdb155d01725d7a52e ]
Cleans the next descriptor to watch (next_to_watch) when cleaning the
TX ring.
Failure to do so can cause invalid memory accesses. If igb_poll() runs
while the controller is reset this can lead to the driver try to free
a skb that was already freed.
(The crash is harder to reproduce with the igb driver, but the same
potential problem exists as the code is identical to igc)
Fixes: 7cc6fd4c60f2 ("igb: Don't bother clearing Tx buffer_info in igb_clean_tx_ring")
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@xxxxxxxxx>
Reported-by: Erez Geva <erez.geva.ext@xxxxxxxxxxx>
Tested-by: Tony Brelinski <tonyx.brelinski@xxxxxxxxx>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/intel/igb/igb_main.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 4b9b5148c916..b40654664025 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -4836,6 +4836,8 @@ static void igb_clean_tx_ring(struct igb_ring *tx_ring)
DMA_TO_DEVICE);
}
+ tx_buffer->next_to_watch = NULL;
+
/* move us one more past the eop_desc for start of next pkt */
tx_buffer++;
i++;
--
2.30.2
