linux-kernel - [PATCH] Revert "spi: simplify devm_spi_register

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20220712135504.1055688-1-yangyingliang@huawei.com>
Date:   Tue, 12 Jul 2022 21:55:04 +0800
From:   Yang Yingliang <yangyingliang@...wei.com>
To:     <linux-kernel@...r.kernel.org>, <linux-spi@...r.kernel.org>
CC:     <broonie@...nel.org>
Subject: [PATCH] Revert "spi: simplify devm_spi_register_controller"

This reverts commit 59ebbe40fb51e307032ae7f63b2749fad2d4635a.

If devm_add_action() fails in devm_add_action_or_reset(),
devm_spi_unregister() will be called, it decreases the
refcount of 'ctlr->dev' to 0, then it will cause uaf in
the drivers that calling spi_put_controller() in error path.

Fixes: 59ebbe40fb51 ("spi: simplify devm_spi_register_controller")
Signed-off-by: Yang Yingliang <yangyingliang@...wei.com>
---
 drivers/spi/spi.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index dc1a324e3271..ef751ccd65be 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -3130,9 +3130,9 @@ int spi_register_controller(struct spi_controller *ctlr)
 }
 EXPORT_SYMBOL_GPL(spi_register_controller);
 
-static void devm_spi_unregister(void *ctlr)
+static void devm_spi_unregister(struct device *dev, void *res)
 {
-	spi_unregister_controller(ctlr);
+	spi_unregister_controller(*(struct spi_controller **)res);
 }
 
 /**
@@ -3151,13 +3151,22 @@ static void devm_spi_unregister(void *ctlr)
 int devm_spi_register_controller(struct device *dev,
 				 struct spi_controller *ctlr)
 {
+	struct spi_controller **ptr;
 	int ret;
 
+	ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
 	ret = spi_register_controller(ctlr);
-	if (ret)
-		return ret;
+	if (!ret) {
+		*ptr = ctlr;
+		devres_add(dev, ptr);
+	} else {
+		devres_free(ptr);
+	}
 
-	return devm_add_action_or_reset(dev, devm_spi_unregister, ctlr);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(devm_spi_register_controller);
 
-- 
2.25.1