The device_unregister() is supposed to be used to unregister devices if device_register() has succeed. And device_unregister() will put device. The caller should not do it again, otherwise, the first call of put_device() will drop the last reference count, then the next call of device_unregister() will UAF on device.
Fixes: 4fb6eabf1037 ("drivers/base/memory.c: cache memory blocks in xarray to accelerate lookup") Signed-off-by: Muchun Song songmuchun@bytedance.com Cc: stable@vger.kernel.org --- drivers/base/memory.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 7222ff9b5e05..084d67fd55cc 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -636,10 +636,9 @@ static int __add_memory_block(struct memory_block *memory) } ret = xa_err(xa_store(&memory_blocks, memory->dev.id, memory, GFP_KERNEL)); - if (ret) { - put_device(&memory->dev); + if (ret) device_unregister(&memory->dev); - } + return ret; }