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From: Alejandro Colomar <alx@kernel.org>
To: linux-hardening@vger.kernel.org
Cc: Alejandro Colomar <alx@kernel.org>,
	alx+linux-hardening@kernel.org,
	 Andreas Schwab <schwab@linux-m68k.org>,
	Andy Shevchenko <andy@kernel.org>,
	 Bartosz Golaszewski <brgl@kernel.org>,
	Daniel Scally <djrscally@gmail.com>,
	 Danilo Krummrich <dakr@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	 Hans Verkuil <hverkuil-cisco@xs4all.nl>,
	Heikki Krogerus <heikki.krogerus@linux.intel.com>,
	 Joe Perches <joe@perches.com>, Johan Hovold <johan@kernel.org>,
	Kees Cook <kees@kernel.org>,
	 Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Len Brown <lenb@kernel.org>,
	 Linus Torvalds <torvalds@linux-foundation.org>,
	Linus Walleij <linusw@kernel.org>,
	 Namhyung Kim <namhyung@kernel.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	 Rob Herring <robh@kernel.org>,
	Sakari Ailus <sakari.ailus@linux.intel.com>,
	 Saravana Kannan <saravanak@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	 Tom Zanussi <zanussi@kernel.org>,
	linux-acpi@vger.kernel.org, driver-core@lists.linux.dev,
	 linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
	linux-gpio@vger.kernel.org,
	 Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Subject: [PATCH v2 2/2] device property: Fix fwnode_name_eq() for empty node names
Date: Thu, 5 Nov 2026 13:46:37 +0100	[thread overview]
Message-ID: <ac9728afa0279375c640b6db0a6ca1dd3d600970.1793882260.git.alx@kernel.org> (raw)
In-Reply-To: <cover.1793882260.git.alx@kernel.org>

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str_has_prefix() returns the prefix length on match and 0 on mismatch,
so the mistmatch case can't be told from "empty prefix matched an empty
string".

For instance: the OF root node's name as returned by
fwnode_get_name() is "" and will return 0 for any name matched against
it and since len is 0 too, fwnode_name_eq() will return true.

Let's use strprefix() instead, which also makes this function simpler.

Fixes: a9c8c738066b7 ("device property: Add fwnode_name_eq()")
Reported-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Cc: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
---
 drivers/base/property.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 51109794d727..7728116e2968 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -692,15 +692,12 @@ const char *fwnode_get_name_prefix(const struct fwnode_handle *fwnode)
 bool fwnode_name_eq(const struct fwnode_handle *fwnode, const char *name)
 {
 	const char *node_name;
-	ptrdiff_t len;
 
 	node_name = fwnode_get_name(fwnode);
 	if (!node_name)
 		return false;
 
-	len = strchrnul(node_name, '@') - node_name;
-
-	return str_has_prefix(node_name, name) == len;
+	return strprefix(node_name, name) == strchrnul(node_name, '@');
 }
 EXPORT_SYMBOL_GPL(fwnode_name_eq);
 
-- 
2.55.0


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  parent reply	other threads:[~2026-11-05 12:46 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-11-05 11:12 [PATCH v1 0/2] Add strprefix() and fix a bug with it Alejandro Colomar
2026-11-05 11:13 ` [PATCH v1 1/2] string: Add strprefix(), and deprecate str_has_prefix() Alejandro Colomar
2026-11-05 11:27   ` Andy Shevchenko
2026-11-05 12:28     ` Alejandro Colomar
2026-11-05 16:14   ` Steven Rostedt
2026-11-05 16:33     ` Alejandro Colomar
2026-11-05 16:50       ` Steven Rostedt
2026-11-05 17:46         ` Alejandro Colomar
2026-11-05 18:08           ` Andy Shevchenko
2026-11-05 18:12             ` Andy Shevchenko
2026-11-05 21:24               ` Alejandro Colomar
2026-11-05 21:48                 ` Linus Torvalds
2026-11-05 22:25                   ` Alejandro Colomar
2026-11-05 23:21                     ` Linus Torvalds
2026-11-06  0:01                       ` Alejandro Colomar
2026-11-05 11:13 ` [PATCH v1 2/2] device property: Fix fwnode_name_eq() for empty node names Alejandro Colomar
2026-11-05 11:24 ` [PATCH v1 0/2] Add strprefix() and fix a bug with it Andy Shevchenko
2026-11-05 11:38   ` Alejandro Colomar
2026-11-05 11:59     ` Andy Shevchenko
2026-11-05 12:30 ` Bartosz Golaszewski
2026-11-05 12:49   ` Alejandro Colomar
2026-11-05 12:46 ` [PATCH v2 " Alejandro Colomar
2026-11-05 12:46   ` [PATCH v2 1/2] string: Add strprefix(), and deprecate str_has_prefix() Alejandro Colomar
2026-11-05 12:51     ` Geert Uytterhoeven
2026-11-05 13:12       ` Alejandro Colomar
2026-11-05 12:46   ` Alejandro Colomar [this message]
2026-11-05 14:01   ` [PATCH v2 0/2] Add strprefix() and fix a bug with it Bartosz Golaszewski
2026-11-05 14:16     ` Alejandro Colomar
2026-11-05 14:42       ` Andy Shevchenko
2026-11-05 15:06         ` Alejandro Colomar
2026-11-05 15:00       ` Bartosz Golaszewski
2026-11-05 15:14         ` Alejandro Colomar
2026-11-05 15:21       ` Krzysztof Kozlowski
2026-11-05 16:27         ` Steven Rostedt
2026-11-05 16:30           ` Krzysztof Kozlowski
2026-11-05 16:42         ` Alejandro Colomar

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