Re: [PATCH] net: usb: lan78xx: Limit packet length to skb->len

From: kernel test robot
Date: Fri Mar 17 2023 - 12:47:08 EST


Hi Szymon,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on net-next/main]
[also build test WARNING on net/main linus/master v6.3-rc2 next-20230317]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Szymon-Heidrich/net-usb-lan78xx-Limit-packet-length-to-skb-len/20230317-233602
patch link: https://lore.kernel.org/r/20230317153217.90145-1-szymon.heidrich%40gmail.com
patch subject: [PATCH] net: usb: lan78xx: Limit packet length to skb->len
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20230318/202303180031.EsiDo4qY-lkp@xxxxxxxxx/config)
compiler: m68k-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/0110af02bdfd214f5cd310013aa19163d6558a7d
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Szymon-Heidrich/net-usb-lan78xx-Limit-packet-length-to-skb-len/20230317-233602
git checkout 0110af02bdfd214f5cd310013aa19163d6558a7d
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash drivers/net/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Link: https://lore.kernel.org/oe-kbuild-all/202303180031.EsiDo4qY-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

drivers/net/usb/lan78xx.c: In function 'lan78xx_rx':
>> drivers/net/usb/lan78xx.c:3600:25: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
3600 | u32 frame_len = size - ETH_FCS_LEN;
| ^~~


vim +3600 drivers/net/usb/lan78xx.c

55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3552
ec4c7e12396b1a John Efstathiades 2021-11-18 3553 static int lan78xx_rx(struct lan78xx_net *dev, struct sk_buff *skb,
ec4c7e12396b1a John Efstathiades 2021-11-18 3554 int budget, int *work_done)
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3555 {
0dd87266c1337d John Efstathiades 2021-11-18 3556 if (skb->len < RX_SKB_MIN_LEN)
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3557 return 0;
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3558
ec4c7e12396b1a John Efstathiades 2021-11-18 3559 /* Extract frames from the URB buffer and pass each one to
ec4c7e12396b1a John Efstathiades 2021-11-18 3560 * the stack in a new NAPI SKB.
ec4c7e12396b1a John Efstathiades 2021-11-18 3561 */
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3562 while (skb->len > 0) {
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3563 u32 rx_cmd_a, rx_cmd_b, align_count, size;
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3564 u16 rx_cmd_c;
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3565 unsigned char *packet;
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3566
bb448f8a60ea93 Chuhong Yuan 2019-07-19 3567 rx_cmd_a = get_unaligned_le32(skb->data);
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3568 skb_pull(skb, sizeof(rx_cmd_a));
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3569
bb448f8a60ea93 Chuhong Yuan 2019-07-19 3570 rx_cmd_b = get_unaligned_le32(skb->data);
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3571 skb_pull(skb, sizeof(rx_cmd_b));
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3572
bb448f8a60ea93 Chuhong Yuan 2019-07-19 3573 rx_cmd_c = get_unaligned_le16(skb->data);
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3574 skb_pull(skb, sizeof(rx_cmd_c));
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3575
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3576 packet = skb->data;
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3577
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3578 /* get the packet length */
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3579 size = (rx_cmd_a & RX_CMD_A_LEN_MASK_);
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3580 align_count = (4 - ((size + RXW_PADDING) % 4)) % 4;
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3581
0110af02bdfd21 Szymon Heidrich 2023-03-17 3582 if (unlikely(size > skb->len)) {
0110af02bdfd21 Szymon Heidrich 2023-03-17 3583 netif_dbg(dev, rx_err, dev->net,
0110af02bdfd21 Szymon Heidrich 2023-03-17 3584 "size err rx_cmd_a=0x%08x\n",
0110af02bdfd21 Szymon Heidrich 2023-03-17 3585 rx_cmd_a);
0110af02bdfd21 Szymon Heidrich 2023-03-17 3586 return 0;
0110af02bdfd21 Szymon Heidrich 2023-03-17 3587 }
0110af02bdfd21 Szymon Heidrich 2023-03-17 3588
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3589 if (unlikely(rx_cmd_a & RX_CMD_A_RED_)) {
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3590 netif_dbg(dev, rx_err, dev->net,
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3591 "Error rx_cmd_a=0x%08x", rx_cmd_a);
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3592 } else {
0110af02bdfd21 Szymon Heidrich 2023-03-17 3593 if (unlikely(size < ETH_FCS_LEN)) {
0110af02bdfd21 Szymon Heidrich 2023-03-17 3594 netif_dbg(dev, rx_err, dev->net,
0110af02bdfd21 Szymon Heidrich 2023-03-17 3595 "size err rx_cmd_a=0x%08x\n",
0110af02bdfd21 Szymon Heidrich 2023-03-17 3596 rx_cmd_a);
0110af02bdfd21 Szymon Heidrich 2023-03-17 3597 return 0;
0110af02bdfd21 Szymon Heidrich 2023-03-17 3598 }
0110af02bdfd21 Szymon Heidrich 2023-03-17 3599
ec4c7e12396b1a John Efstathiades 2021-11-18 @3600 u32 frame_len = size - ETH_FCS_LEN;
ec4c7e12396b1a John Efstathiades 2021-11-18 3601 struct sk_buff *skb2;
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3602
ec4c7e12396b1a John Efstathiades 2021-11-18 3603 skb2 = napi_alloc_skb(&dev->napi, frame_len);
ec4c7e12396b1a John Efstathiades 2021-11-18 3604 if (!skb2)
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3605 return 0;
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3606
ec4c7e12396b1a John Efstathiades 2021-11-18 3607 memcpy(skb2->data, packet, frame_len);
ec4c7e12396b1a John Efstathiades 2021-11-18 3608
ec4c7e12396b1a John Efstathiades 2021-11-18 3609 skb_put(skb2, frame_len);
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3610
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3611 lan78xx_rx_csum_offload(dev, skb2, rx_cmd_a, rx_cmd_b);
ec21ecf0aad279 Dave Stevenson 2018-06-25 3612 lan78xx_rx_vlan_offload(dev, skb2, rx_cmd_a, rx_cmd_b);
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3613
ec4c7e12396b1a John Efstathiades 2021-11-18 3614 /* Processing of the URB buffer must complete once
ec4c7e12396b1a John Efstathiades 2021-11-18 3615 * it has started. If the NAPI work budget is exhausted
ec4c7e12396b1a John Efstathiades 2021-11-18 3616 * while frames remain they are added to the overflow
ec4c7e12396b1a John Efstathiades 2021-11-18 3617 * queue for delivery in the next NAPI polling cycle.
ec4c7e12396b1a John Efstathiades 2021-11-18 3618 */
ec4c7e12396b1a John Efstathiades 2021-11-18 3619 if (*work_done < budget) {
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3620 lan78xx_skb_return(dev, skb2);
ec4c7e12396b1a John Efstathiades 2021-11-18 3621 ++(*work_done);
ec4c7e12396b1a John Efstathiades 2021-11-18 3622 } else {
ec4c7e12396b1a John Efstathiades 2021-11-18 3623 skb_queue_tail(&dev->rxq_overflow, skb2);
ec4c7e12396b1a John Efstathiades 2021-11-18 3624 }
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3625 }
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3626
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3627 skb_pull(skb, size);
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3628
ec4c7e12396b1a John Efstathiades 2021-11-18 3629 /* skip padding bytes before the next frame starts */
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3630 if (skb->len)
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3631 skb_pull(skb, align_count);
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3632 }
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3633
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3634 return 1;
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3635 }
55d7de9de6c30a Woojung.Huh@xxxxxxxxxxxxx 2015-07-30 3636

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https://github.com/intel/lkp-tests