Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.15 264/779] i2c: Fix a potential use after free | Date | Mon, 15 Aug 2022 19:58:28 +0200 |
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From: Xu Wang <vulab@iscas.ac.cn>
[ 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 <vulab@iscas.ac.cn> [wsa: added comment to the code, added Fixes tag] Signed-off-by: Wolfram Sang <wsa@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- 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 cfbef70e8ba7..8fb065caf30b 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -2464,8 +2464,9 @@ 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); -- 2.35.1
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