From: Jakub Kicinski <kuba@kernel.org>
To: Sam Edwards <cfsworks@gmail.com>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>,
"David S . Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Paolo Abeni <pabeni@redhat.com>,
Russell King <rmk+kernel@armlinux.org.uk>,
Maxime Chevallier <maxime.chevallier@bootlin.com>,
Ovidiu Panait <ovidiu.panait.rb@renesas.com>,
Vladimir Oltean <vladimir.oltean@nxp.com>,
Baruch Siach <baruch@tkos.co.il>,
Serge Semin <fancer.lancer@gmail.com>,
netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/3] stmmac crash/stall fixes when under memory pressure
Date: Tue, 17 Mar 2026 20:27:18 -0700 [thread overview]
Message-ID: <20260317202718.3a5433c4@kernel.org> (raw)
In-Reply-To: <20260316021009.262358-1-CFSworks@gmail.com>
On Sun, 15 Mar 2026 19:10:06 -0700 Sam Edwards wrote:
> This is a pair of bugfixes for the stmmac driver's receive pipeline. These
> issues occur when stmmac_rx_refill() does not (fully) succeed, which happens
> more frequently when free memory is low.
>
> The first patch closes Bugzilla bug #221010, where stmmac_rx() can circle
> around to a still-dirty descriptor (with a NULL buffer pointer), mistake it for
> a filled descriptor (due to OWN=0), and attempt to dereference the buffer.
>
> In testing that patch, I discovered a second issue: starvation of available RX
> buffers causes the NIC to stop sending interrupts; if the driver stops polling,
> it will wait indefinitely for an interrupt that will never come. (Note: the
> first patch makes this issue more prominent -- mostly because it lets the
> system survive long enough to exhibit it -- but doesn't *cause* it.) The second
> patch addresses that problem as well.
>
> The first two patches are minimal and intended for stable. The third is a
> general cleanup that removes the `limit` clamp and *solves* the issue of the
> loop mistaking dirty entries for filled ones, rather than *avoiding* it.
> Because this final patch changes the range of stmmac_rx_dirty()'s possible
> return values, it's intended for -next, not stable.
Please (ask your LLM to) read
https://www.kernel.org/doc/html/next/process/maintainer-netdev.html
You can't submit fixes and next changes in one go.
Please have a critical look at the commit messages.
They are very bloviated and not slop looking.
--
pw-bot: cr
next prev parent reply other threads:[~2026-03-18 3:27 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-16 2:10 [PATCH 0/3] stmmac crash/stall fixes when under memory pressure Sam Edwards
2026-03-16 2:10 ` [PATCH 1/3] net: stmmac: Fix NULL deref when RX encounters a dirty descriptor Sam Edwards
2026-03-16 2:10 ` [PATCH 2/3] net: stmmac: Prevent indefinite RX stall on buffer exhaustion Sam Edwards
2026-03-16 2:10 ` [PATCH 3/3] net: stmmac: Remove stmmac_rx()'s `limit`, check desc validity instead Sam Edwards
2026-03-18 3:27 ` Jakub Kicinski [this message]
2026-03-18 3:46 ` [PATCH 0/3] stmmac crash/stall fixes when under memory pressure Sam Edwards
2026-03-18 22:11 ` Jakub Kicinski
2026-03-18 23:18 ` Sam Edwards
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