From: Vinicius Costa Gomes Date: Fri, 14 May 2021 00:31:04 +0000 (-0700) Subject: igb: Fix use-after-free error during reset X-Git-Tag: v5.14-rc2~28^2~62^2~9 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7b292608db23ccbbfbfa50cdb155d01725d7a52e;p=thirdparty%2Fkernel%2Flinux.git igb: Fix use-after-free error during reset 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 Reported-by: Erez Geva Tested-by: Tony Brelinski Signed-off-by: Tony Nguyen --- diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index 7e6435dc7e80c..a61e2e5e95c00 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -4835,6 +4835,8 @@ 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++;