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Commit 26925042 authored by Bob Copeland's avatar Bob Copeland Committed by John W. Linville
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ath5k: manipulate rxlink and descriptor address under rxbuf lock 



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: default avatarBob Copeland <me@bobcopeland.com>
Acked-by: default avatarNick Kossifidis <mickflemm@gmail.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent c57ca815

drivers/net/wireless/ath/ath5k/base.c

+2 −3
Original line number Original line Diff line number Diff line
@@ -1618,9 +1618,8 @@ ath5k_rx_start(struct ath5k_softc *sc) 
	ATH5K_DBG(sc, ATH5K_DEBUG_RESET, "cachelsz %u rxbufsize %u\n",

	ATH5K_DBG(sc, ATH5K_DEBUG_RESET, "cachelsz %u rxbufsize %u\n",

		sc->cachelsz, sc->rxbufsize);

		sc->cachelsz, sc->rxbufsize);





	sc->rxlink = NULL;



	spin_lock_bh(&sc->rxbuflock);

	spin_lock_bh(&sc->rxbuflock);

	sc->rxlink = NULL;

	list_for_each_entry(bf, &sc->rxbuf, list) {

	list_for_each_entry(bf, &sc->rxbuf, list) {

		ret = ath5k_rxbuf_setup(sc, bf);

		ret = ath5k_rxbuf_setup(sc, bf);

		if (ret != 0) {

		if (ret != 0) {
@@ -1629,9 +1628,9 @@ ath5k_rx_start(struct ath5k_softc *sc) 
		}

		}

	}

	}

	bf = list_first_entry(&sc->rxbuf, struct ath5k_buf, list);

	bf = list_first_entry(&sc->rxbuf, struct ath5k_buf, list);

	ath5k_hw_set_rxdp(ah, bf->daddr);

	spin_unlock_bh(&sc->rxbuflock);

	spin_unlock_bh(&sc->rxbuflock);





	ath5k_hw_set_rxdp(ah, bf->daddr);

	ath5k_hw_start_rx_dma(ah);	/* enable recv descriptors */

	ath5k_hw_start_rx_dma(ah);	/* enable recv descriptors */

	ath5k_mode_setup(sc);		/* set filters, etc. */

	ath5k_mode_setup(sc);		/* set filters, etc. */

	ath5k_hw_start_rx_pcu(ah);	/* re-enable PCU/DMA engine */

	ath5k_hw_start_rx_pcu(ah);	/* re-enable PCU/DMA engine */