From 7147a13135ee717397969d33a139204dfe793022 Mon Sep 17 00:00:00 2001 From: Michal Kazior Date: Mon, 26 May 2014 12:02:58 +0200 Subject: [PATCH] ath10k: protect src_ring state with ce_lock in tx_sg() It was possible to read invalid state of CE ring buffer indexes. This could lead to scatter-gather transfer failure in mid-way and crash firmware later by leaving garbage data on the ring. Reported-By: Avery Pennarun Signed-off-by: Michal Kazior Signed-off-by: Kalle Valo --- drivers/net/wireless/ath/ath10k/pci.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/ath/ath10k/pci.c b/drivers/net/wireless/ath/ath10k/pci.c index 71ab110a4c4d..b1eb9153c7f4 100644 --- a/drivers/net/wireless/ath/ath10k/pci.c +++ b/drivers/net/wireless/ath/ath10k/pci.c @@ -762,13 +762,17 @@ static int ath10k_pci_hif_tx_sg(struct ath10k *ar, u8 pipe_id, struct ath10k_pci_pipe *pci_pipe = &ar_pci->pipe_info[pipe_id]; struct ath10k_ce_pipe *ce_pipe = pci_pipe->ce_hdl; struct ath10k_ce_ring *src_ring = ce_pipe->src_ring; - unsigned int nentries_mask = src_ring->nentries_mask; - unsigned int sw_index = src_ring->sw_index; - unsigned int write_index = src_ring->write_index; + unsigned int nentries_mask; + unsigned int sw_index; + unsigned int write_index; int err, i; spin_lock_bh(&ar_pci->ce_lock); + nentries_mask = src_ring->nentries_mask; + sw_index = src_ring->sw_index; + write_index = src_ring->write_index; + if (unlikely(CE_RING_DELTA(nentries_mask, write_index, sw_index - 1) < n_items)) { err = -ENOBUFS; -- 2.34.1