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 DF89D79C6 for ; Mon, 19 Jun 2023 10:40:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5D655C433C8; Mon, 19 Jun 2023 10:40:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1687171236; bh=2JLfz6tfQEPJb7CnVemWAmMS6q+Kz6PN2Zzsfl1N9Jc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZFMYAkSA1g1Ioaro7ClBh8529Ww2f5RuGZo72MwhtJM90OpZsObVO0JkXC/wmJtlm pSO1l+n7MMVpV+nIc2dQcznDmm/8zBo44+E5TqSm1KlSYMAoe8CmFSbPZcrd9gHaN1 Rsmf3mLjTySC7J0Jbe0KkWAYUAS4YkSOkH8l+k7o= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Hans de Goede , Linus Walleij , Sebastian Reichel , Sasha Levin Subject: [PATCH 4.19 01/49] power: supply: ab8500: Fix external_power_changed race Date: Mon, 19 Jun 2023 12:29:39 +0200 Message-ID: <20230619102129.934197194@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230619102129.856988902@linuxfoundation.org> References: <20230619102129.856988902@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore 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 a5299ce4e96f3e8930e9c051b28d8093ada87b08 ] ab8500_btemp_external_power_changed() dereferences di->btemp_psy, which gets sets in ab8500_btemp_probe() like this: di->btemp_psy = devm_power_supply_register(dev, &ab8500_btemp_desc, &psy_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 ab8500_btemp_external_power_changed() may get called while di->btemp_psy 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 di->btemp_psy, so ab8500_btemp_external_power_changed() can simply directly use the passed in psy argument which is always valid. And the same applies to ab8500_fg_external_power_changed(). Signed-off-by: Hans de Goede Reviewed-by: Linus Walleij Signed-off-by: Sebastian Reichel Signed-off-by: Sasha Levin --- drivers/power/supply/ab8500_btemp.c | 6 ++---- drivers/power/supply/ab8500_fg.c | 6 ++---- 2 files changed, 4 insertions(+), 8 deletions(-) diff --git a/drivers/power/supply/ab8500_btemp.c b/drivers/power/supply/ab8500_btemp.c index 0fd24577112eb..0bec8b90667c8 100644 --- a/drivers/power/supply/ab8500_btemp.c +++ b/drivers/power/supply/ab8500_btemp.c @@ -919,10 +919,8 @@ static int ab8500_btemp_get_ext_psy_data(struct device *dev, void *data) */ static void ab8500_btemp_external_power_changed(struct power_supply *psy) { - struct ab8500_btemp *di = power_supply_get_drvdata(psy); - - class_for_each_device(power_supply_class, NULL, - di->btemp_psy, ab8500_btemp_get_ext_psy_data); + class_for_each_device(power_supply_class, NULL, psy, + ab8500_btemp_get_ext_psy_data); } /* ab8500 btemp driver interrupts and their respective isr */ diff --git a/drivers/power/supply/ab8500_fg.c b/drivers/power/supply/ab8500_fg.c index 675f9d0e8471e..d0cbd7189a622 100644 --- a/drivers/power/supply/ab8500_fg.c +++ b/drivers/power/supply/ab8500_fg.c @@ -2380,10 +2380,8 @@ static int ab8500_fg_init_hw_registers(struct ab8500_fg *di) */ static void ab8500_fg_external_power_changed(struct power_supply *psy) { - struct ab8500_fg *di = power_supply_get_drvdata(psy); - - class_for_each_device(power_supply_class, NULL, - di->fg_psy, ab8500_fg_get_ext_psy_data); + class_for_each_device(power_supply_class, NULL, psy, + ab8500_fg_get_ext_psy_data); } /** -- 2.39.2