This is a note to let you know that I've just added the patch titled net: stmmac: fix TSO DMA API usage causing oops to the 6.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-stmmac-fix-tso-dma-api-usage-causing-oops.patch and it can be found in the queue-6.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 7db091e222bec2ba7fbad34cbcf8a5195bfdf7b5 Author: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx> Date: Fri Dec 6 12:40:11 2024 +0000 net: stmmac: fix TSO DMA API usage causing oops [ Upstream commit 4c49f38e20a57f8abaebdf95b369295b153d1f8e ] Commit 66600fac7a98 ("net: stmmac: TSO: Fix unbalanced DMA map/unmap for non-paged SKB data") moved the assignment of tx_skbuff_dma[]'s members to be later in stmmac_tso_xmit(). The buf (dma cookie) and len stored in this structure are passed to dma_unmap_single() by stmmac_tx_clean(). The DMA API requires that the dma cookie passed to dma_unmap_single() is the same as the value returned from dma_map_single(). However, by moving the assignment later, this is not the case when priv->dma_cap.addr64 > 32 as "des" is offset by proto_hdr_len. This causes problems such as: dwc-eth-dwmac 2490000.ethernet eth0: Tx DMA map failed and with DMA_API_DEBUG enabled: DMA-API: dwc-eth-dwmac 2490000.ethernet: device driver tries to +free DMA memory it has not allocated [device address=0x000000ffffcf65c0] [size=66 bytes] Fix this by maintaining "des" as the original DMA cookie, and use tso_des to pass the offset DMA cookie to stmmac_tso_allocator(). Full details of the crashes can be found at: https://lore.kernel.org/all/d8112193-0386-4e14-b516-37c2d838171a@xxxxxxxxxx/ https://lore.kernel.org/all/klkzp5yn5kq5efgtrow6wbvnc46bcqfxs65nz3qy77ujr5turc@bwwhelz2l4dw/ Reported-by: Jon Hunter <jonathanh@xxxxxxxxxx> Reported-by: Thierry Reding <thierry.reding@xxxxxxxxx> Fixes: 66600fac7a98 ("net: stmmac: TSO: Fix unbalanced DMA map/unmap for non-paged SKB data") Tested-by: Jon Hunter <jonathanh@xxxxxxxxxx> Signed-off-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx> Reviewed-by: Furong Xu <0x1207@xxxxxxxxx> Link: https://patch.msgid.link/E1tJXcx-006N4Z-PC@xxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 766213ee82c1..cf7b59b8cc64 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -4220,8 +4220,8 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev) struct stmmac_txq_stats *txq_stats; struct stmmac_tx_queue *tx_q; u32 pay_len, mss, queue; + dma_addr_t tso_des, des; u8 proto_hdr_len, hdr; - dma_addr_t des; bool set_ic; int i; @@ -4317,14 +4317,15 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev) /* If needed take extra descriptors to fill the remaining payload */ tmp_pay_len = pay_len - TSO_MAX_BUFF_SIZE; + tso_des = des; } else { stmmac_set_desc_addr(priv, first, des); tmp_pay_len = pay_len; - des += proto_hdr_len; + tso_des = des + proto_hdr_len; pay_len = 0; } - stmmac_tso_allocator(priv, des, tmp_pay_len, (nfrags == 0), queue); + stmmac_tso_allocator(priv, tso_des, tmp_pay_len, (nfrags == 0), queue); /* In case two or more DMA transmit descriptors are allocated for this * non-paged SKB data, the DMA buffer address should be saved to