6.15-stable review patch. If anyone has any objections, please let me know.
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From: Masami Hiramatsu (Google) mhiramat@kernel.org
commit f5de469990f19569627ea0dd56536ff5a13beaa3 upstream.
If msdc_prepare_data() fails to map the DMA region, the request is not prepared for data receiving, but msdc_start_data() proceeds the DMA with previous setting. Since this will lead a memory corruption, we have to stop the request operation soon after the msdc_prepare_data() fails to prepare it.
Signed-off-by: Masami Hiramatsu (Google) mhiramat@kernel.org Fixes: 208489032bdd ("mmc: mediatek: Add Mediatek MMC driver") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/174972756982.3337526.6755001617701603082.stgit@mhi... Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/mmc/host/mtk-sd.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-)
--- a/drivers/mmc/host/mtk-sd.c +++ b/drivers/mmc/host/mtk-sd.c @@ -834,6 +834,11 @@ static void msdc_prepare_data(struct msd } }
+static bool msdc_data_prepared(struct mmc_data *data) +{ + return data->host_cookie & MSDC_PREPARE_FLAG; +} + static void msdc_unprepare_data(struct msdc_host *host, struct mmc_data *data) { if (data->host_cookie & MSDC_ASYNC_FLAG) @@ -1466,8 +1471,18 @@ static void msdc_ops_request(struct mmc_ WARN_ON(!host->hsq_en && host->mrq); host->mrq = mrq;
- if (mrq->data) + if (mrq->data) { msdc_prepare_data(host, mrq->data); + if (!msdc_data_prepared(mrq->data)) { + /* + * Failed to prepare DMA area, fail fast before + * starting any commands. + */ + mrq->cmd->error = -ENOSPC; + mmc_request_done(mmc_from_priv(host), mrq); + return; + } + }
/* if SBC is required, we have HW option and SW option. * if HW option is enabled, and SBC does not have "special" flags,