linux-kernel - [PATCH 5.10 13/93] gpio: pca953x: do not ignore i2c errors

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: <20211004125035.016468268@linuxfoundation.org>
Date:   Mon,  4 Oct 2021 14:52:11 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Andrey Gusakov <andrey.gusakov@...entembedded.com>,
        Nikita Yushchenko <nikita.yoush@...entembedded.com>,
        Bartosz Golaszewski <brgl@...ev.pl>
Subject: [PATCH 5.10 13/93] gpio: pca953x: do not ignore i2c errors

From: Andrey Gusakov <andrey.gusakov@...entembedded.com>

commit 540cffbab8b8e6c52a4121666ca18d6e94586ed2 upstream.

Per gpio_chip interface, error shall be proparated to the caller.

Attempt to silent diagnostics by returning zero (as written in the
comment) is plain wrong, because the zero return can be interpreted by
the caller as the gpio value.

Cc: stable@...r.kernel.org
Signed-off-by: Andrey Gusakov <andrey.gusakov@...entembedded.com>
Signed-off-by: Nikita Yushchenko <nikita.yoush@...entembedded.com>
Signed-off-by: Bartosz Golaszewski <brgl@...ev.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/gpio/gpio-pca953x.c |   11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -467,15 +467,8 @@ static int pca953x_gpio_get_value(struct
 	mutex_lock(&chip->i2c_lock);
 	ret = regmap_read(chip->regmap, inreg, &reg_val);
 	mutex_unlock(&chip->i2c_lock);
-	if (ret < 0) {
-		/*
-		 * NOTE:
-		 * diagnostic already emitted; that's all we should
-		 * do unless gpio_*_value_cansleep() calls become different
-		 * from their nonsleeping siblings (and report faults).
-		 */
-		return 0;
-	}
+	if (ret < 0)
+		return ret;
 
 	return !!(reg_val & bit);
 }