From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4E8BE10975 for ; Mon, 19 Jun 2023 10:33:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C99EDC433C9; Mon, 19 Jun 2023 10:33:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1687170788; bh=PsRJJ5ZxMa7cs8GT5ohChX59MmmNPMIucMA3Mt/cmNs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c16rK4WnH2q0mCQuXw0ZSayvY4rHAPRT/bKFzgADYKknpQ4Mh9zZwQC8irUhWvBIt 66NY5dBg2uAqymoe2tJ+jB+KewyaeVBrVE2N7zLPLeFzczjfvLM/j8r0FfA1Feduq7 0XZkYpGREYsXDqkgF4D9v9wKNIaAEL8eHVq81Aac= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Orson Zhai , Chunyan Zhang , Hans de Goede , Baolin Wang , Sebastian Reichel , Sasha Levin Subject: [PATCH 6.3 010/187] power: supply: sc27xx: Fix external_power_changed race Date: Mon, 19 Jun 2023 12:27:08 +0200 Message-ID: <20230619102158.107048036@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230619102157.579823843@linuxfoundation.org> References: <20230619102157.579823843@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Hans de Goede [ Upstream commit 4d5c129d6c8993fe96e9ae712141eedcb9ca68c2 ] sc27xx_fgu_external_power_changed() dereferences data->battery, which gets sets in ab8500_btemp_probe() like this: data->battery = devm_power_supply_register(dev, &sc27xx_fgu_desc, &fgu_cfg); As soon as devm_power_supply_register() has called device_add() the external_power_changed callback can get called. So there is a window where sc27xx_fgu_external_power_changed() may get called while data->battery has not been set yet leading to a NULL pointer dereference. Fixing this is easy. The external_power_changed callback gets passed the power_supply which will eventually get stored in data->battery, so sc27xx_fgu_external_power_changed() can simply directly use the passed in psy argument which is always valid. After this change sc27xx_fgu_external_power_changed() is reduced to just "power_supply_changed(psy);" and it has the same prototype. While at it simply replace it with making the external_power_changed callback directly point to power_supply_changed. Cc: Orson Zhai Cc: Chunyan Zhang Signed-off-by: Hans de Goede Reviewed-by: Baolin Wang Signed-off-by: Sebastian Reichel Signed-off-by: Sasha Levin --- drivers/power/supply/sc27xx_fuel_gauge.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/drivers/power/supply/sc27xx_fuel_gauge.c b/drivers/power/supply/sc27xx_fuel_gauge.c index 632977f84b954..bd23c4d9fed43 100644 --- a/drivers/power/supply/sc27xx_fuel_gauge.c +++ b/drivers/power/supply/sc27xx_fuel_gauge.c @@ -733,13 +733,6 @@ static int sc27xx_fgu_set_property(struct power_supply *psy, return ret; } -static void sc27xx_fgu_external_power_changed(struct power_supply *psy) -{ - struct sc27xx_fgu_data *data = power_supply_get_drvdata(psy); - - power_supply_changed(data->battery); -} - static int sc27xx_fgu_property_is_writeable(struct power_supply *psy, enum power_supply_property psp) { @@ -774,7 +767,7 @@ static const struct power_supply_desc sc27xx_fgu_desc = { .num_properties = ARRAY_SIZE(sc27xx_fgu_props), .get_property = sc27xx_fgu_get_property, .set_property = sc27xx_fgu_set_property, - .external_power_changed = sc27xx_fgu_external_power_changed, + .external_power_changed = power_supply_changed, .property_is_writeable = sc27xx_fgu_property_is_writeable, .no_thermal = true, }; -- 2.39.2