Grabbing an ath5k_buf then dropping the lock is racy because the
referenced descriptor can be obtained in another thread and released
before the buffer is handed to the hardware.  Likewise, manipulating
sc->rxlink without the lock can lead to having multiple self-linked
hardware descriptors.

Changes-licensed-under: 3-Clause-BSD

Signed-off-by: Bob Copeland <m...@bobcopeland.com>
---
 drivers/net/wireless/ath5k/base.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/ath5k/base.c 
b/drivers/net/wireless/ath5k/base.c
index fde8525..2d24fa5 100644
--- a/drivers/net/wireless/ath5k/base.c
+++ b/drivers/net/wireless/ath5k/base.c
@@ -1598,9 +1598,8 @@ ath5k_rx_start(struct ath5k_softc *sc)
        ATH5K_DBG(sc, ATH5K_DEBUG_RESET, "cachelsz %u rxbufsize %u\n",
                sc->cachelsz, sc->rxbufsize);
 
-       sc->rxlink = NULL;
-
        spin_lock_bh(&sc->rxbuflock);
+       sc->rxlink = NULL;
        list_for_each_entry(bf, &sc->rxbuf, list) {
                ret = ath5k_rxbuf_setup(sc, bf);
                if (ret != 0) {
@@ -1609,9 +1608,9 @@ ath5k_rx_start(struct ath5k_softc *sc)
                }
        }
        bf = list_first_entry(&sc->rxbuf, struct ath5k_buf, list);
+       ath5k_hw_set_rxdp(ah, bf->daddr);
        spin_unlock_bh(&sc->rxbuflock);
 
-       ath5k_hw_set_rxdp(ah, bf->daddr);
        ath5k_hw_start_rx_dma(ah);      /* enable recv descriptors */
        ath5k_mode_setup(sc);           /* set filters, etc. */
        ath5k_hw_start_rx_pcu(ah);      /* re-enable PCU/DMA engine */
-- 
1.6.0.6


_______________________________________________
ath5k-devel mailing list
ath5k-devel@lists.ath5k.org
https://lists.ath5k.org/mailman/listinfo/ath5k-devel

Reply via email to