Re: [kbuild] drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c:721 dpaa2_eth_build_sg_fd_single_buf() warn: overwrite may leak 'sgt_buf'
From: Philip Li
Date: Wed May 19 2021 - 22:02:47 EST
On Thu, Apr 29, 2021 at 10:29:27PM +0800, Dan Carpenter wrote:
> [ Why is kbuild sending out 8 month old bug reports??? -dan ]
hi Dan, it's possible such issue is just discovered by the newly
generated randconfig arm-randconfig-m031-20210428.
>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: acd3d28594536e9096c1ea76c5867d8a68babef6
> commit: 5d8dccf8bad96bdc5bd5594344ff67539cf3a733 dpaa2-eth: add a dpaa2_eth_ prefix to all functions in dpaa2-eth.c
> config: arm-randconfig-m031-20210428 (attached as .config)
> compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
>
> smatch warnings:
> drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c:721 dpaa2_eth_build_sg_fd_single_buf() warn: overwrite may leak 'sgt_buf'
>
> vim +/sgt_buf +721 drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
>
> 5d8dccf8bad96b drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-08-31 696 static int dpaa2_eth_build_sg_fd_single_buf(struct dpaa2_eth_priv *priv,
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 697 struct sk_buff *skb,
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 698 struct dpaa2_fd *fd)
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 699 {
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 700 struct device *dev = priv->net_dev->dev.parent;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 701 struct dpaa2_eth_sgt_cache *sgt_cache;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 702 struct dpaa2_sg_entry *sgt;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 703 struct dpaa2_eth_swa *swa;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 704 dma_addr_t addr, sgt_addr;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 705 void *sgt_buf = NULL;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 706 int sgt_buf_size;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 707 int err;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 708
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 709 /* Prepare the HW SGT structure */
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 710 sgt_cache = this_cpu_ptr(priv->sgt_cache);
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 711 sgt_buf_size = priv->tx_data_offset + sizeof(struct dpaa2_sg_entry);
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 712
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 713 if (sgt_cache->count == 0)
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 714 sgt_buf = kzalloc(sgt_buf_size + DPAA2_ETH_TX_BUF_ALIGN,
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 715 GFP_ATOMIC);
>
> sgt_buf is assigned here.
>
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 716 else
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 717 sgt_buf = sgt_cache->buf[--sgt_cache->count];
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 718 if (unlikely(!sgt_buf))
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 719 return -ENOMEM;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 720
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 @721 sgt_buf = PTR_ALIGN(sgt_buf, DPAA2_ETH_TX_BUF_ALIGN);
>
> We're losing track of the original "sgt_buf" pointer so we won't be
> able to pass it to kfree().
>
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 722 sgt = (struct dpaa2_sg_entry *)(sgt_buf + priv->tx_data_offset);
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 723
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 724 addr = dma_map_single(dev, skb->data, skb->len, DMA_BIDIRECTIONAL);
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 725 if (unlikely(dma_mapping_error(dev, addr))) {
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 726 err = -ENOMEM;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 727 goto data_map_failed;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 728 }
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 729
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 730 /* Fill in the HW SGT structure */
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 731 dpaa2_sg_set_addr(sgt, addr);
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 732 dpaa2_sg_set_len(sgt, skb->len);
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 733 dpaa2_sg_set_final(sgt, true);
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 734
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 735 /* Store the skb backpointer in the SGT buffer */
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 736 swa = (struct dpaa2_eth_swa *)sgt_buf;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 737 swa->type = DPAA2_ETH_SWA_SINGLE;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 738 swa->single.skb = skb;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 739 swa->sg.sgt_size = sgt_buf_size;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 740
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 741 /* Separately map the SGT buffer */
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 742 sgt_addr = dma_map_single(dev, sgt_buf, sgt_buf_size, DMA_BIDIRECTIONAL);
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 743 if (unlikely(dma_mapping_error(dev, sgt_addr))) {
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 744 err = -ENOMEM;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 745 goto sgt_map_failed;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 746 }
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 747
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 748 dpaa2_fd_set_offset(fd, priv->tx_data_offset);
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 749 dpaa2_fd_set_format(fd, dpaa2_fd_sg);
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 750 dpaa2_fd_set_addr(fd, sgt_addr);
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 751 dpaa2_fd_set_len(fd, skb->len);
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 752 dpaa2_fd_set_ctrl(fd, FD_CTRL_PTA);
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 753
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 754 if (priv->tx_tstamp && skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)
> 5d8dccf8bad96b drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-08-31 755 dpaa2_eth_enable_tx_tstamp(fd, sgt_buf);
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 756
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 757 return 0;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 758
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 759 sgt_map_failed:
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 760 dma_unmap_single(dev, addr, skb->len, DMA_BIDIRECTIONAL);
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 761 data_map_failed:
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 762 if (sgt_cache->count >= DPAA2_ETH_SGT_CACHE_SIZE)
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 763 kfree(sgt_buf);
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 764 else
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 765 sgt_cache->buf[sgt_cache->count++] = sgt_buf;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 766
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 767 return err;
> d70446ee1f406e drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c Ioana Ciornei 2020-06-29 768 }
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
> _______________________________________________
> kbuild mailing list -- kbuild@xxxxxxxxxxxx
> To unsubscribe send an email to kbuild-leave@xxxxxxxxxxxx