From 5e693ceeb3eefcb6f3390c756b664f79bb60fb3c Mon Sep 17 00:00:00 2001 From: Xu Wang Date: Wed, 28 Feb 2024 00:55:02 +0000 Subject: [PATCH] i2c: Fix a potential use after free stable inclusion from stable-v4.19.307 commit 23a191b132cd87f746c62f3dc27da33683d85829 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I946KM CVE: CVE-2019-25162 Reference: https://git.kernel.org/stable/c/23a191b132cd87f746c62f3dc27da33683d85829 --------------------------------------------------------------- [ Upstream commit e4c72c06c367758a14f227c847f9d623f1994ecf ] Free the adap structure only after we are done using it. This patch just moves the put_device() down a bit to avoid the use after free. Fixes: 611e12ea0f12 ("i2c: core: manage i2c bus device refcount in i2c_[get|put]_adapter") Signed-off-by: Xu Wang [wsa: added comment to the code, added Fixes tag] Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/i2c-core-base.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 540c77e04ad2..fdf644b53972 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -2312,8 +2312,9 @@ void i2c_put_adapter(struct i2c_adapter *adap) if (!adap) return; - put_device(&adap->dev); module_put(adap->owner); + /* Should be last, otherwise we risk use-after-free with 'adap' */ + put_device(&adap->dev); } EXPORT_SYMBOL(i2c_put_adapter); -- Gitee