Messages in this thread Patch in this message | | | From | Jiri Slaby <> | Subject | [PATCH 3.12 47/84] iwlwifi: pcie: fix access to scratch buffer | Date | Mon, 17 Oct 2016 09:51:34 +0200 |
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From: Sara Sharon <sara.sharon@intel.com>
3.12-stable review patch. If anyone has any objections, please let me know.
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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: Jiri Slaby <jslaby@suse.cz> --- drivers/net/wireless/iwlwifi/pcie/tx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/iwlwifi/pcie/tx.c b/drivers/net/wireless/iwlwifi/pcie/tx.c index 911a15074ffb..6c769009587b 100644 --- a/drivers/net/wireless/iwlwifi/pcie/tx.c +++ b/drivers/net/wireless/iwlwifi/pcie/tx.c @@ -1328,9 +1328,9 @@ 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 */ -- 2.10.1
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