linux-kernel - Re: [PATCH v2 1/1] net: fec: handle page_pool_dev_alloc

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <3c48a608-b2d9-4210-9718-1518a758abbb@intel.com>
Date: Mon, 13 Jan 2025 10:55:08 -0800
From: Jacob Keller <jacob.e.keller@...el.com>
To: Kevin Groeneveld <kgroeneveld@...brook.com>, Wei Fang <wei.fang@....com>,
	Shenwei Wang <shenwei.wang@....com>, Clark Wang <xiaoning.wang@....com>,
	Andrew Lunn <andrew+netdev@...n.ch>, "David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, "Paolo
 Abeni" <pabeni@...hat.com>, <imx@...ts.linux.dev>, <netdev@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 1/1] net: fec: handle page_pool_dev_alloc_pages error



On 1/13/2025 7:48 AM, Kevin Groeneveld wrote:
> The fec_enet_update_cbd function calls page_pool_dev_alloc_pages but did
> not handle the case when it returned NULL. There was a WARN_ON(!new_page)
> but it would still proceed to use the NULL pointer and then crash.
> 
> This case does seem somewhat rare but when the system is under memory
> pressure it can happen. One case where I can duplicate this with some
> frequency is when writing over a smbd share to a SATA HDD attached to an
> imx6q.
> 
> Setting /proc/sys/vm/min_free_kbytes to higher values also seems to solve
> the problem for my test case. But it still seems wrong that the fec driver
> ignores the memory allocation error and can crash.
> 
> This commit handles the allocation error by dropping the current packet.
> 
> Fixes: 95698ff6177b5 ("net: fec: using page pool to manage RX buffers")
> Signed-off-by: Kevin Groeneveld <kgroeneveld@...brook.com>
> ---

Reviewed-by: Jacob Keller <jacob.e.keller@...el.com>