| Message ID | E1tJXcx-006N4Z-PC@rmk-PC.armlinux.org.uk (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [net] net: stmmac: fix TSO DMA API usage causing oops | expand |
On Fri, 06 Dec 2024 12:40:11 +0000, "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk> wrote: > 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") Much appreciated for this fix. Reviewed-by: Furong Xu <0x1207@gmail.com>
Hello: This patch was applied to netdev/net.git (main) by Jakub Kicinski <kuba@kernel.org>: On Fri, 06 Dec 2024 12:40:11 +0000 you wrote: > 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. > > [...] Here is the summary with links: - [net] net: stmmac: fix TSO DMA API usage causing oops https://git.kernel.org/netdev/net/c/4c49f38e20a5 You are awesome, thank you!
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 9b262cdad60b..c81ea8cdfe6e 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -4192,8 +4192,8 @@ 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; @@ -4289,14 +4289,15 @@ 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
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> --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)