mmc: sdhci: fix NULL dereference in sdhci_request() tuning
Commit 473b095a72a9 ("mmc: sdhci: fix incorrect command used in tuning")
introduced a NULL dereference at resume-time if an SD 3.0 host controller
raises the SDHCI_NEEDS_TUNING flag while no card is inserted. Seen on an
OLPC XO-4 with sdhci-pxav3, but presumably affects other controllers too.
Signed-off-by: Chris Ball <cjb@laptop.org>
Cc: stable <stable@vger.kernel.org> [3.3+]
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 949e18c..c7851c0 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1315,16 +1315,19 @@
*/
if ((host->flags & SDHCI_NEEDS_RETUNING) &&
!(present_state & (SDHCI_DOING_WRITE | SDHCI_DOING_READ))) {
- /* eMMC uses cmd21 while sd and sdio use cmd19 */
- tuning_opcode = mmc->card->type == MMC_TYPE_MMC ?
- MMC_SEND_TUNING_BLOCK_HS200 :
- MMC_SEND_TUNING_BLOCK;
- spin_unlock_irqrestore(&host->lock, flags);
- sdhci_execute_tuning(mmc, tuning_opcode);
- spin_lock_irqsave(&host->lock, flags);
+ if (mmc->card) {
+ /* eMMC uses cmd21 but sd and sdio use cmd19 */
+ tuning_opcode =
+ mmc->card->type == MMC_TYPE_MMC ?
+ MMC_SEND_TUNING_BLOCK_HS200 :
+ MMC_SEND_TUNING_BLOCK;
+ spin_unlock_irqrestore(&host->lock, flags);
+ sdhci_execute_tuning(mmc, tuning_opcode);
+ spin_lock_irqsave(&host->lock, flags);
- /* Restore original mmc_request structure */
- host->mrq = mrq;
+ /* Restore original mmc_request structure */
+ host->mrq = mrq;
+ }
}
if (mrq->sbc && !(host->flags & SDHCI_AUTO_CMD23))