| Message ID | 20210323031512.12234-1-lyl2019@mail.ustc.edu.cn |
|---|---|
| State | New |
| Headers | show |
| Series | thunderbolt: Fix a double put in tb_cfg_read_raw | expand |
diff --git a/drivers/thunderbolt/ctl.c b/drivers/thunderbolt/ctl.c index f1aeaff9f368..bb60269c89ab 100644 --- a/drivers/thunderbolt/ctl.c +++ b/drivers/thunderbolt/ctl.c @@ -890,11 +890,11 @@ struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer, res = tb_cfg_request_sync(ctl, req, timeout_msec); - tb_cfg_request_put(req); - if (res.err != -ETIMEDOUT) break; + tb_cfg_request_put(req); + /* Wait a bit (arbitrary time) until we send a retry */ usleep_range(10, 100); }
In tb_cfg_read_raw, req is allocated by tb_cfg_request_alloc() with an initial reference. Before calling tb_cfg_request_sync(), there is no refcount inc operation. tb_cfg_request_sync() calls tb_cfg_request(..,req,..) and if the callee failed, the initial reference of req is dropped and req is freed. Later in tb_cfg_read_raw before the err check, tb_cfg_request_put(req) is called again. It may cause error in race. My patch puts tb_cfg_request_put(req) after the err check finished to avoid unexpected result. Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn> --- drivers/thunderbolt/ctl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)