Re: [dpdk-stable] [PATCH] net/mlx5: fix mbufs replenishment check for zipped CQEs

[Raslan Darawsheh <rasland@nvidia.com>]

Hi,
> -----Original Message-----
> From: Alexander Kozyrev <akozyrev@nvidia.com>
> Sent: Wednesday, August 4, 2021 9:23 AM
> To: dev@dpdk.org
> Cc: stable@dpdk.org; Raslan Darawsheh <rasland@nvidia.com>; Slava
> Ovsiienko <viacheslavo@nvidia.com>; Matan Azrad <matan@nvidia.com>
> Subject: [PATCH] net/mlx5: fix mbufs replenishment check for zipped CQEs
> 
> A core dump is being generated with the following call stack:
> 0 _mm256_storeu_si256 (__A=..., __P=0x80)
> 1 rte_mov32 (src=0x2299c9140 "", dst=0x80)
> 2 rte_memcpy_aligned (n=60, src=0x2299c9140, dst=0x80)
> 3 rte_memcpy (n=60, src=0x2299c9140, dst=0x80)
> 4 mprq_buf_to_pkt (strd_cnt=1, strd_idx=0, buf=0x2299c8a00, len=60,
> pkt=0x18345f0c0, rxq=0x18345ef40)
> 5 rxq_copy_mprq_mbuf_v (rxq=0x18345ef40, pkts=0x7f76e0ff6d18,
> pkts_n=5)
> 6 rxq_burst_mprq_v (rxq=0x18345ef40, pkts=0x7f76e0ff6d18, pkts_n=46,
> err=0x7f76e0ff6a28, no_cq=0x7f76e0ff6a27)
> 7 mlx5_rx_burst_mprq_vec (dpdk_rxq=0x18345ef40, pkts=0x7f76e0ff6a88,
> pkts_n=128)
> 8 rte_eth_rx_burst (nb_pkts=128, rx_pkts=0x7f76e0ff6a88,
> queue_id=<optimized out>, port_id=<optimized out>)
> 
> This crash is caused by an attempt to copy previously uncompressed CQEs
> into non-allocated mbufs. There is a check to make sure we only use
> allocated mbufs in the rxq_burst_mprq_v() function, but it is done only
> before the main processing loop. Leftovers of compressed CQEs session are
> handled before that loop and may lead to the mbufs overflow as seen.
> 
> Move the check for replenished mbufs up to protect uncompressed CQEs
> session leftovers from accessing non-allocated mbufs after the
> mlx5_rx_mprq_replenish_bulk_mbuf() function is invoked.
> 
> Bugzilla ID: 746
> Fixes: 0f20acbf5e ("net/mlx5: implement vectorized MPRQ burst")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Alexander Kozyrev <akozyrev@nvidia.com>
> Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
> ---

Patch applied to next-net-mlx,

Kindest regards,
Raslan Darawsheh