From 6acdefd0bd34390abf2cc2ec4390673b0093f812 Mon Sep 17 00:00:00 2001 From: Peter Collingbourne Date: Thu, 14 Jan 2021 12:14:05 -0800 Subject: [PATCH] mmc: core: don't initialize block size from ext_csd if not present commit b503087445ce7e45fabdee87ca9e460d5b5b5168 upstream. If extended CSD was not available, the eMMC driver would incorrectly set the block size to 0, as the data_sector_size field of ext_csd was never initialized. This issue was exposed by commit 817046ecddbc ("block: Align max_hw_sectors to logical blocksize") which caused max_sectors and max_hw_sectors to be set to 0 after setting the block size to 0, resulting in a kernel panic in bio_split when attempting to read from the device. Fix it by only reading the block size from ext_csd if it is available. Fixes: a5075eb94837 ("mmc: block: Allow disabling 512B sector size emulation") Signed-off-by: Peter Collingbourne Reviewed-by: Damien Le Moal Link: https://linux-review.googlesource.com/id/If244d178da4d86b52034459438fec295b02d6e60 Acked-by: Adrian Hunter Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210114201405.2934886-1-pcc@google.com Signed-off-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman --- drivers/mmc/core/queue.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index 81b8d5ede484..9cee10e44e2f 100644 --- a/drivers/mmc/core/queue.c +++ b/drivers/mmc/core/queue.c @@ -370,8 +370,10 @@ static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card) "merging was advertised but not possible"); blk_queue_max_segments(mq->queue, mmc_get_max_segments(host)); - if (mmc_card_mmc(card)) + if (mmc_card_mmc(card) && card->ext_csd.data_sector_size) { block_size = card->ext_csd.data_sector_size; + WARN_ON(block_size != 512 && block_size != 4096); + } blk_queue_logical_block_size(mq->queue, block_size); /*