diff options
| author | Chris Ball <cjb@laptop.org> | 2012-11-05 19:29:49 (GMT) |
|---|---|---|
| committer | Chris Ball <cjb@laptop.org> | 2012-11-07 20:02:05 (GMT) |
| commit | 14efd957209461bbdf285bf0d67e931955d04a4c (patch) | |
| tree | e4e057308b28671aece200cde1516210f17af611 | |
| parent | 657d59823c095e8f03e2744d765f53700331ff8f (diff) | |
| download | linux-14efd957209461bbdf285bf0d67e931955d04a4c.tar.xz | |
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+]
| -rw-r--r-- | drivers/mmc/host/sdhci.c | 23 |
1 files changed, 13 insertions, 10 deletions
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 @@ static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq) */ 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); - - /* Restore original mmc_request structure */ - host->mrq = mrq; + 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; + } } if (mrq->sbc && !(host->flags & SDHCI_AUTO_CMD23)) |