From: Dinghao Liu <dinghao.liu@xxxxxxxxxx> commit e4befc121df03dc8ed2ac1031c98f9538e244bae upstream. When copy_from_user() returns an error code, there is a runtime PM usage counter imbalance. Fix this by moving copy_from_user() to the beginning of this function. Fixes: 7b6c1b4c0e1e ("usb: musb: fix runtime PM in debugfs") Signed-off-by: Dinghao Liu <dinghao.liu@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Bin Liu <b-liu@xxxxxx> Link: https://lore.kernel.org/r/20200525025049.3400-7-b-liu@xxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/musb/musb_debugfs.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- a/drivers/usb/musb/musb_debugfs.c +++ b/drivers/usb/musb/musb_debugfs.c @@ -168,6 +168,11 @@ static ssize_t musb_test_mode_write(stru u8 test; char buf[24]; + memset(buf, 0x00, sizeof(buf)); + + if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count))) + return -EFAULT; + pm_runtime_get_sync(musb->controller); test = musb_readb(musb->mregs, MUSB_TESTMODE); if (test) { @@ -176,11 +181,6 @@ static ssize_t musb_test_mode_write(stru goto ret; } - memset(buf, 0x00, sizeof(buf)); - - if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count))) - return -EFAULT; - if (strstarts(buf, "force host full-speed")) test = MUSB_TEST_FORCE_HOST | MUSB_TEST_FORCE_FS;