From: Vinicius Costa Gomes vinicius.gomes@intel.com
[ 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@intel.com Reported-by: Erez Geva erez.geva.ext@siemens.com Tested-by: Tony Brelinski tonyx.brelinski@intel.com Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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++;