From: Simon Horman <horms@kernel•org>
To: leitao@debian•org
Cc: 'Simon Horman' <horms@kernel•org>,
andrew+netdev@lunn•ch, davem@davemloft•net, edumazet@google•com,
kuba@kernel•org, pabeni@redhat•com, k-keiichi@bx•jp.nec.com,
satyam@infradead•org, akpm@linux-foundation•org,
thepacketgeek@gmail•com, asantostc@gmail•com,
gustavold@gmail•com, netdev@vger•kernel.org,
linux-kernel@vger•kernel.org, kernel-team@meta•com
Subject: Re: [PATCH net 3/3] netconsole: propagate device name truncation in dev_name_store()
Date: Sun, 26 Apr 2026 09:39:05 +0100 [thread overview]
Message-ID: <20260426083904.1130399-2-horms@kernel.org> (raw)
In-Reply-To: <20260423-netconsole_ai_fixes-v1-3-92b8b7de9a2c@debian.org>
From: 'Simon Horman' <horms@kernel•org>
This is an AI-generated review of your patch. The human sending this
email has considered the AI review valid, or at least plausible.
Full review at: https://sashiko.dev
---
netconsole: propagate device name truncation in dev_name_store()
This commit rejects interface name writes that exceed the size of the
destination buffer to avoid silently truncating names and binding to
unintended devices.
> diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
> index 4bef003d9df64..3914fb90f9afd 100644
> --- a/drivers/net/netconsole.c
> +++ b/drivers/net/netconsole.c
> @@ -816,6 +816,9 @@ static ssize_t dev_name_store(struct config_item *item, const char *buf,
> {
> struct netconsole_target *nt = to_target(item);
>
> + if (count >= IFNAMSIZ)
> + return -ENAMETOOLONG;
> +
Does this check incorrectly reject valid maximum-length interface names when
written with a trailing newline?
Standard userspace tools like echo append a trailing newline when writing to
configfs attributes. If userspace writes a 15-character name, the count will
be exactly 16 bytes.
Since IFNAMSIZ is 16, the condition count >= IFNAMSIZ evaluates to true,
causing dev_name_store() to reject the valid input with -ENAMETOOLONG.
Prior to this patch, strscpy() safely truncated the trailing newline by
copying the 15 characters and a NUL terminator.
next prev parent reply other threads:[~2026-04-26 8:40 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-23 9:41 [PATCH net 0/3] netconsole: configfs store callback fixes Breno Leitao
2026-04-23 9:41 ` [PATCH net 1/3] netconsole: return count instead of strnlen(buf, count) from store callbacks Breno Leitao
2026-04-26 8:46 ` Simon Horman
2026-04-27 10:00 ` Breno Leitao
2026-04-23 9:41 ` [PATCH net 2/3] netconsole: avoid clobbering userdatum value on truncated write Breno Leitao
2026-04-26 8:35 ` Simon Horman
2026-04-27 10:51 ` Breno Leitao
2026-04-23 9:41 ` [PATCH net 3/3] netconsole: propagate device name truncation in dev_name_store() Breno Leitao
2026-04-26 8:39 ` Simon Horman [this message]
2026-04-27 10:26 ` Breno Leitao
2026-04-28 9:23 ` Simon Horman
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