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authorSara Sharon <sara.sharon@intel.com>2016-06-09 17:19:35 +0300
committerMister Oyster <oysterized@gmail.com>2017-04-11 10:58:39 +0200
commit1d68297aaf84668954e113ccf5e4164bc35f2d4d (patch)
treea8a65ccdac19fcf656b96565a295cafda73d705f
parent0effc36ebef26caf6c851ec18396d027e83c3f8d (diff)
iwlwifi: pcie: fix access to scratch buffer
commit d5d0689aefc59c6a5352ca25d7e6d47d03f543ce upstream. This fixes a pretty ancient bug that hasn't manifested itself until now. The scratchbuf for command queue is allocated only for 32 slots but is accessed with the queue write pointer - which can be up to 256. Since the scratch buf size was 16 and there are up to 256 TFDs we never passed a page boundary when accessing the scratch buffer, but when attempting to increase the size of the scratch buffer a panic was quick to follow when trying to access the address resulted in a page boundary. Signed-off-by: Sara Sharon <sara.sharon@intel.com> Fixes: 38c0f334b359 ("iwlwifi: use coherent DMA memory for command header") Signed-off-by: Luca Coelho <luciano.coelho@intel.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
-rw-r--r--drivers/net/wireless/iwlwifi/pcie/tx.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/net/wireless/iwlwifi/pcie/tx.c b/drivers/net/wireless/iwlwifi/pcie/tx.c
index f05962c32..2e3a0d73f 100644
--- a/drivers/net/wireless/iwlwifi/pcie/tx.c
+++ b/drivers/net/wireless/iwlwifi/pcie/tx.c
@@ -1311,9 +1311,9 @@ static int iwl_pcie_enqueue_hcmd(struct iwl_trans *trans,
/* start the TFD with the scratchbuf */
scratch_size = min_t(int, copy_size, IWL_HCMD_SCRATCHBUF_SIZE);
- memcpy(&txq->scratchbufs[q->write_ptr], &out_cmd->hdr, scratch_size);
+ memcpy(&txq->scratchbufs[idx], &out_cmd->hdr, scratch_size);
iwl_pcie_txq_build_tfd(trans, txq,
- iwl_pcie_get_scratchbuf_dma(txq, q->write_ptr),
+ iwl_pcie_get_scratchbuf_dma(txq, idx),
scratch_size, 1);
/* map first command fragment, if any remains */