[PATCH 4.19 026/243] i2c: core: fix use after free in of_i2c_notify

Greg Kroah-Hartman
2019-12-11T15:16:50Z

From: Wen Yang <wenyang@linux.alibaba.com>

[ Upstream commit a4c2fec16f5e6a5fee4865e6e0e91e2bc2d10f37 ]

We can't use "adap->dev" after it has been freed.

Fixes: 5bf4fa7daea6 ("i2c: break out OF support into separate file")
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/i2c/i2c-core-of.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/i2c-core-of.c b/drivers/i2c/i2c-core-of.c
index 0f01cdba9d2c6..14d4884996968 100644
--- a/drivers/i2c/i2c-core-of.c
+++ b/drivers/i2c/i2c-core-of.c
@@ -253,14 +253,14 @@ static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
}

client = of_i2c_register_device(adap, rd->dn);
- put_device(&adap->dev);
-
if (IS_ERR(client)) {
dev_err(&adap->dev, "failed to create client for '%pOF'\n",
rd->dn);
+ put_device(&adap->dev);
of_node_clear_flag(rd->dn, OF_POPULATED);
return notifier_from_errno(PTR_ERR(client));
}
+ put_device(&adap->dev);
break;
case OF_RECONFIG_CHANGE_REMOVE:
/* already depopulated? */
--
2.20.1