5.4-stable review patch. If anyone has any objections, please let me know.
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From: Joe Hattori joe@pf.is.s.u-tokyo.ac.jp
[ Upstream commit 93c66fbc280747ea700bd6199633d661e3c819b3 ]
powercap_register_control_type() calls device_register(), but does not release the refcount of the device when it fails.
Call put_device() before returning an error to balance the refcount.
Since the kfree(control_type) will be done by powercap_release(), remove the lines in powercap_register_control_type() before returning the error.
This bug was found by an experimental verifier that I am developing.
Signed-off-by: Joe Hattori joe@pf.is.s.u-tokyo.ac.jp Link: https://patch.msgid.link/20250110010554.1583411-1-joe@pf.is.s.u-tokyo.ac.jp [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/powercap/powercap_sys.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/powercap/powercap_sys.c b/drivers/powercap/powercap_sys.c index 7a3109a538813..fe5d05da7ce7a 100644 --- a/drivers/powercap/powercap_sys.c +++ b/drivers/powercap/powercap_sys.c @@ -627,8 +627,7 @@ struct powercap_control_type *powercap_register_control_type( dev_set_name(&control_type->dev, "%s", name); result = device_register(&control_type->dev); if (result) { - if (control_type->allocated) - kfree(control_type); + put_device(&control_type->dev); return ERR_PTR(result); } idr_init(&control_type->idr);