firmware: qemu_fw_cfg: fix NULL-pointer deref on duplicate entries

Commit fe3c60684377 ("firmware: Fix a reference count leak.") "fixed"
a kobject leak in the file registration helper by properly calling
kobject_put() for the entry in case registration of the object fails
(e.g. due to a name collision).

This would however result in a NULL pointer dereference when the
release function tries to remove the never added entry from the
fw_cfg_entry_cache list.

Fix this by moving the list-removal out of the release function.

Note that the offending commit was one of the benign looking umn.edu
fixes which was reviewed but not reverted. [1][2]

[1] https://lore.kernel.org/r/202105051005.49BFABCE@keescook
[2] https://lore.kernel.org/all/[email protected]

Fixes: fe3c60684377 ("firmware: Fix a reference count leak.")
Cc: [email protected]      # 5.8
Cc: Qiushi Wu <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Johan Hovold <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michael S. Tsirkin <[email protected]>

0 files changed, 0 insertions, 0 deletions