diff options
| author | Martin Kaiser <[email protected]> | 2023-01-31 10:00:57 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <[email protected]> | 2023-02-06 10:44:38 +0100 |
| commit | c6dd307144235f2abd97c974883398176345af9f (patch) | |
| tree | 89e0ca24dfe78d06153ccbf82719db5ac662ae5d | |
| parent | 7f0c12449aa91867efb00f080fb34c77d40c81e6 (diff) | |
staging: r8188eu: clean up NULL check for rcu pointer
Clean up the NULL check for padapter->pnetdev->rx_handler_data.
The current code calls rcu_dereference while it holds the rcu read lock
and checks the pointer after releasing the lock. An rcu pointer may only be
used between calls to rcu_read_lock and rcu_read_unlock.
Replace the check with rcu_access_pointer. My understanding is that this
function returns the value of the pointer and needs no locking. We can
then check the pointer but we must not dereference it.
Signed-off-by: Martin Kaiser <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
| -rw-r--r-- | drivers/staging/r8188eu/core/rtw_xmit.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/drivers/staging/r8188eu/core/rtw_xmit.c b/drivers/staging/r8188eu/core/rtw_xmit.c index 91f92ec5ef69..18941320e70e 100644 --- a/drivers/staging/r8188eu/core/rtw_xmit.c +++ b/drivers/staging/r8188eu/core/rtw_xmit.c @@ -1631,18 +1631,14 @@ s32 rtw_xmit(struct adapter *padapter, struct sk_buff **ppkt) struct xmit_priv *pxmitpriv = &padapter->xmitpriv; struct xmit_frame *pxmitframe = NULL; struct mlme_priv *pmlmepriv = &padapter->mlmepriv; - void *br_port = NULL; s32 res; pxmitframe = rtw_alloc_xmitframe(pxmitpriv); if (!pxmitframe) return -1; - rcu_read_lock(); - br_port = rcu_dereference(padapter->pnetdev->rx_handler_data); - rcu_read_unlock(); - - if (br_port && check_fwstate(pmlmepriv, WIFI_STATION_STATE | WIFI_ADHOC_STATE)) { + if (rcu_access_pointer(padapter->pnetdev->rx_handler_data) && + check_fwstate(pmlmepriv, WIFI_STATION_STATE | WIFI_ADHOC_STATE)) { res = rtw_br_client_tx(padapter, ppkt); if (res == -1) { rtw_free_xmitframe(pxmitpriv, pxmitframe); |