From: Daniel Pharos <danielpharos@hotmail.com>
To: "dev@dpdk.org" <dev@dpdk.org>
Subject: [dpdk-dev] MLX5: Array written to out-of-bounds when freeing memory
Date: Fri, 18 Jan 2019 17:36:39 +0000 [thread overview]
Message-ID: <AM0PR0402MB38266DACB800B22E8ACCA782D39C0@AM0PR0402MB3826.eurprd04.prod.outlook.com> (raw)
Hi,
Recently I had the privilege of some play-time on a IBM Power 9 machine with a Mellanox MLX5-card in it. However, I encountered a seg fault problem using DPDK and DPDK-pktgen. It's the exact same one as somebody else encountered (also on a Power 9) here:
https://bugzilla.redhat.com/show_bug.cgi?id=1634159#c10
It looks like it's writing out-of-bounds on the "free"-array in DPDK.
Reverting the patch that added the bulk-free ( http://mails.dpdk.org/archives/dev/2017-June/069154.html ) indeed makes DPDK and pktgen function correctly. A better workaround I found is to change drivers/net/mlx5/mlx5_rxtx.h, line 580 to:
if (likely((m->pool == pool) && (blk_n != elts_n))) {
I'm not familiar enough with the code to understand why the array is being written to out-of-bounds, and why it's only happening on a Power 9 machine. Unfortunately, my play-time is now over, but I thought I'd report this issue anyway, so hopefully it can be investigated and fixed properly.
Kind regards,
DanielPharos
next reply other threads:[~2019-01-18 17:36 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-18 17:36 Daniel Pharos [this message]
2019-01-19 7:15 ` Yongseok Koh
2019-01-19 12:16 ` Daniel Pharos
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