| From stable+bounces-225502-greg=kroah.com@vger.kernel.org Mon Mar 16 07:06:18 2026 |
| From: Rahul Sharma <black.hawk@163.com> |
| Date: Mon, 16 Mar 2026 14:03:50 +0800 |
| Subject: net: stmmac: fix TSO DMA API usage causing oops |
| To: gregkh@linuxfoundation.org, stable@vger.kernel.org |
| Cc: linux-kernel@vger.kernel.org, "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>, Jon Hunter <jonathanh@nvidia.com>, Thierry Reding <thierry.reding@gmail.com>, Furong Xu <0x1207@gmail.com>, Jakub Kicinski <kuba@kernel.org>, Rahul Sharma <black.hawk@163.com> |
| Message-ID: <20260316060350.2568-1-black.hawk@163.com> |
| |
| From: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk> |
| |
| [ 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@nvidia.com/ |
| https://lore.kernel.org/all/klkzp5yn5kq5efgtrow6wbvnc46bcqfxs65nz3qy77ujr5turc@bwwhelz2l4dw/ |
| |
| Reported-by: Jon Hunter <jonathanh@nvidia.com> |
| Reported-by: Thierry Reding <thierry.reding@gmail.com> |
| Fixes: 66600fac7a98 ("net: stmmac: TSO: Fix unbalanced DMA map/unmap for non-paged SKB data") |
| Tested-by: Jon Hunter <jonathanh@nvidia.com> |
| Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> |
| Reviewed-by: Furong Xu <0x1207@gmail.com> |
| Link: https://patch.msgid.link/E1tJXcx-006N4Z-PC@rmk-PC.armlinux.org.uk |
| Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
| [ The context change is due to the commit 041cc86b3653 |
| ("net: stmmac: Enable TSO on VLANs") in v6.11 which is irrelevant to |
| the logic of this patch. ] |
| Signed-off-by: Rahul Sharma <black.hawk@163.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 7 ++++--- |
| 1 file changed, 4 insertions(+), 3 deletions(-) |
| |
| --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c |
| +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c |
| @@ -4034,9 +4034,9 @@ static netdev_tx_t stmmac_tso_xmit(struc |
| int tmp_pay_len = 0, first_tx; |
| struct stmmac_tx_queue *tx_q; |
| bool has_vlan, set_ic; |
| + dma_addr_t tso_des, des; |
| u8 proto_hdr_len, hdr; |
| u32 pay_len, mss; |
| - dma_addr_t des; |
| int i; |
| |
| tx_q = &priv->tx_queue[queue]; |
| @@ -4120,14 +4120,15 @@ static netdev_tx_t stmmac_tso_xmit(struc |
| |
| /* 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 |
