From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vinicius Costa Gomes Date: Thu, 13 May 2021 17:31:04 -0700 Subject: [Intel-wired-lan] [PATCH net-queue v1 2/2] igb: Fix user-after-free error during reset In-Reply-To: <20210514003104.1360697-1-vinicius.gomes@intel.com> References: <20210514003104.1360697-1-vinicius.gomes@intel.com> Message-ID: <20210514003104.1360697-2-vinicius.gomes@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: Cleans the next descriptor to watch (next_to_watch) when cleaning the TX ring. Failure to do so can cause invalid memory accesses. If igc_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 --- 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 fb3d69586db7..7d1b97f1deef 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -4841,6 +4841,8 @@ 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++; -- 2.31.1