From 30e87ade8d678c25a8546cf38c0b498fa5cb27d3 Mon Sep 17 00:00:00 2001 From: Matt Vollrath Date: Tue, 24 Feb 2026 18:28:33 -0500 Subject: [PATCH] e1000/e1000e: Fix leak in DMA error cleanup [ Upstream commit e94eaef11142b01f77bf8ba4d0b59720b7858109 ] If an error is encountered while mapping TX buffers, the driver should unmap any buffers already mapped for that skb. Because count is incremented after a successful mapping, it will always match the correct number of unmappings needed when dma_error is reached. Decrementing count before the while loop in dma_error causes an off-by-one error. If any mapping was successful before an unsuccessful mapping, exactly one DMA mapping would leak. In these commits, a faulty while condition caused an infinite loop in dma_error: Commit 03b1320dfcee ("e1000e: remove use of skb_dma_map from e1000e driver") Commit 602c0554d7b0 ("e1000: remove use of skb_dma_map from e1000 driver") Commit c1fa347f20f1 ("e1000/e1000e/igb/igbvf/ixgb/ixgbe: Fix tests of unsigned in *_tx_map()") fixed the infinite loop, but introduced the off-by-one error. This issue may still exist in the igbvf driver, but I did not address it in this patch. Fixes: c1fa347f20f1 ("e1000/e1000e/igb/igbvf/ixgb/ixgbe: Fix tests of unsigned in *_tx_map()") Assisted-by: Claude:claude-4.6-opus Signed-off-by: Matt Vollrath Signed-off-by: Tony Nguyen Signed-off-by: Sasha Levin --- drivers/net/ethernet/intel/e1000/e1000_main.c | 2 -- drivers/net/ethernet/intel/e1000e/netdev.c | 2 -- 2 files changed, 4 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c index 7f078ec9c14c..15160427c8b3 100644 --- a/drivers/net/ethernet/intel/e1000/e1000_main.c +++ b/drivers/net/ethernet/intel/e1000/e1000_main.c @@ -2952,8 +2952,6 @@ static int e1000_tx_map(struct e1000_adapter *adapter, dma_error: dev_err(&pdev->dev, "TX DMA map failed\n"); buffer_info->dma = 0; - if (count) - count--; while (count--) { if (i == 0) diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index 75896602e732..3e3903269610 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -5654,8 +5654,6 @@ static int e1000_tx_map(struct e1000_ring *tx_ring, struct sk_buff *skb, dma_error: dev_err(&pdev->dev, "Tx DMA map failed\n"); buffer_info->dma = 0; - if (count) - count--; while (count--) { if (i == 0)