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From: Khadem Ullah <14pwcse1224@uetpeshawar.edu.pk>
To: dsosnowski@nvidia.com, thomas@monjalon.net,
	andrew.rybchenko@oktetlabs.ru
Cc: dev@dpdk.org, rasland@nvidia.com, stable@dpdk.org,
	viacheslavo@nvidia.com, orika@nvidia.com, suanmingm@nvidia.com,
	matan@nvidia.com
Subject: Re: [PATCH] net/mlx5: fix crash when using meter in transfer flow
Date: Mon, 21 Jul 2025 07:38:12 -0400	[thread overview]
Message-ID: <20250721113822.1029342-1-14pwcse1224@uetpeshawar.edu.pk> (raw)
In-Reply-To: <20250721105819.2ci66fl7bzikwb22@ds-vm-debian.local>

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Hi Dariusz,
Thanks for the feedback. Agreed, this check only papers over a deeper issue with
multi-process lifecycle in ethdev.

If the primary process exits after freeing ethdev data, all subsequent PMD-level
calls (e.g., dev_infos_get) in secondary are inherently unsafe due to dangling
pointers.

Unless ethdev explicitly invalidates the port (or secondary process detects
primary exit), the current behavior results in use-after-free regardless of PMD.

For now, this patch avoids a crash in one case (dev_infos_get), but long-term
a proper ethdev-level solution is needed — either by:
- Marking ports invalid on primary exit,
- Notifying secondaries to teardown,
- Or refusing API access after shared data disappears.

Until then, we can keep this as a safety patch to prevent segfaults in common test scenarios.

  reply	other threads:[~2025-07-21 11:39 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-07-21  7:38 [PATCH] net/mlx5: fix crash when secondary queries dev info after primary exits Khadem Ullah
2025-07-21 10:58 ` Dariusz Sosnowski
2025-07-21 11:38   ` Khadem Ullah [this message]
2025-07-21 11:46   ` Ivan Malov
2025-07-21 11:59     ` Thomas Monjalon
2025-07-21 14:01       ` Dariusz Sosnowski
2025-07-21 14:50   ` Stephen Hemminger
  -- strict thread matches above, loose matches on Subject: below --
2025-07-02 12:36 [PATCH] net/mlx5: fix crash when using meter in transfer flow Khadem Ullah
2025-07-15 17:39 ` Dariusz Sosnowski
2025-07-15 17:51   ` Dariusz Sosnowski
2025-07-16  7:23     ` Khadem Ullah
2025-07-16 10:55       ` Dariusz Sosnowski

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