[PATCH 5.17 480/772] misc: ocxl: fix possible double free in ocxl_file_register_afu

Greg Kroah-Hartman
2022-06-07T21:19:29Z

From: Hangyu Hua <hbh25y@gmail.com>

[ Upstream commit 950cf957fe34d40d63dfa3bf3968210430b6491e ]

info_release() will be called in device_unregister() when info->dev's
reference count is 0. So there is no need to call ocxl_afu_put() and
kfree() again.

Fix this by adding free_minor() and return to err_unregister error path.

Fixes: 75ca758adbaf ("ocxl: Create a clear delineation between ocxl backend & frontend")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220418085758.38145-1-hbh25y@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/misc/ocxl/file.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/misc/ocxl/file.c b/drivers/misc/ocxl/file.c
index d881f5e40ad9..6777c419a8da 100644
--- a/drivers/misc/ocxl/file.c
+++ b/drivers/misc/ocxl/file.c
@@ -556,7 +556,9 @@ int ocxl_file_register_afu(struct ocxl_afu *afu)

err_unregister:
ocxl_sysfs_unregister_afu(info); // safe to call even if register failed
+ free_minor(info);
device_unregister(&info->dev);
+ return rc;
err_put:
ocxl_afu_put(afu);
free_minor(info);
--
2.35.1