Re: [PATCH net v3 2/2] mlx5: fix possible ptp queue fifo use-after-free

[kernel test robot <lkp@intel.com>]

Hi Vadim,

I love your patch! Yet something to improve:

[auto build test ERROR on net/master]

url:    https://github.com/intel-lab-lkp/linux/commits/Vadim-Fedorenko/mlx5-fix-skb-leak-while-fifo-resync-and-push/20230128-120805
patch link:    https://lore.kernel.org/r/20230126010206.13483-3-vfedorenko%40novek.ru
patch subject: [PATCH net v3 2/2] mlx5: fix possible ptp queue fifo use-after-free
config: i386-randconfig-a015 (https://download.01.org/0day-ci/archive/20230129/202301290528.ZvflGIBO-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
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/2516a9785583b92ac82262a813203de696096ccd
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Vadim-Fedorenko/mlx5-fix-skb-leak-while-fifo-resync-and-push/20230128-120805
        git checkout 2516a9785583b92ac82262a813203de696096ccd
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   drivers/net/ethernet/mellanox/mlx5/core/en/ptp.c:93:18: warning: unused variable 'skb' [-Wunused-variable]
           struct sk_buff *skb;
                           ^
   drivers/net/ethernet/mellanox/mlx5/core/en/ptp.c:92:30: warning: unused variable 'hwts' [-Wunused-variable]
           struct skb_shared_hwtstamps hwts = {};
                                       ^
>> drivers/net/ethernet/mellanox/mlx5/core/en/ptp.c:102:2: error: expected identifier or '('
           while (skb_cc != skb_id && (skb = mlx5e_skb_fifo_pop(&ptpsq->skb_fifo))) {
           ^
   drivers/net/ethernet/mellanox/mlx5/core/en/ptp.c:110:2: error: expected identifier or '('
           if (!skb)
           ^
   drivers/net/ethernet/mellanox/mlx5/core/en/ptp.c:113:2: error: expected identifier or '('
           return true;
           ^
>> drivers/net/ethernet/mellanox/mlx5/core/en/ptp.c:114:1: error: extraneous closing brace ('}')
   }
   ^
   2 warnings and 4 errors generated.


vim +102 drivers/net/ethernet/mellanox/mlx5/core/en/ptp.c

    88	
    89	static bool mlx5e_ptp_skb_fifo_ts_cqe_resync(struct mlx5e_ptpsq *ptpsq, u16 skb_cc,
    90						     u16 skb_id, int budget)
    91	{
    92		struct skb_shared_hwtstamps hwts = {};
    93		struct sk_buff *skb;
    94	
    95		ptpsq->cq_stats->resync_event++;
    96	
    97		if (skb_cc > skb_id || PTP_WQE_CTR2IDX(ptpsq->skb_fifo_pc) < skb_id)
    98			pr_err_ratelimited("mlx5e: out-of-order ptp cqe\n");
    99			return false;
   100		}
   101	
 > 102		while (skb_cc != skb_id && (skb = mlx5e_skb_fifo_pop(&ptpsq->skb_fifo))) {
   103			hwts.hwtstamp = mlx5e_skb_cb_get_hwts(skb)->cqe_hwtstamp;
   104			skb_tstamp_tx(skb, &hwts);
   105			ptpsq->cq_stats->resync_cqe++;
   106			napi_consume_skb(skb, budget);
   107			skb_cc = PTP_WQE_CTR2IDX(ptpsq->skb_fifo_cc);
   108		}
   109	
   110		if (!skb)
   111			return false;
   112	
   113		return true;
 > 114	}
   115	

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