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mmc: block: Fix error path in mmc_blk_probe()

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Returning zero to indicate success, when we actually have failed to probe
is wrong. As a matter of fact, it leads to that mmc_blk_remove() gets
called at a card removal and then triggers "NULL pointer dereference"
splats. This is because mmc_blk_remove() relies on data structures and
pointers to be setup from mmc_blk_probe(), of course.

There have been no errors reported about this, which is most likely because
mmc_blk_probe() never fails like this. Nevertheless, let's fix the code by
propagating the error codes correctly and prevent us from leaking memory by
calling also destroy_workqueue() in the error path.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20210303122049.151986-4-ulf.hansson@linaro.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Ulf Hansson 2021-03-03 13:20:49 +01:00
parent ce999ed15e
commit 6f1d324766
1 changed files with 15 additions and 7 deletions
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22
drivers/mmc/core/block.c
View file

@ -2876,6 +2876,7 @@ static void mmc_blk_remove_debugfs(struct mmc_card *card,
static int mmc_blk_probe(struct mmc_card *card)
{
struct mmc_blk_data *md, *part_md;
int ret = 0;
/*
* Check that the card supports the command class(es) we need.
@ -2893,19 +2894,24 @@ static int mmc_blk_probe(struct mmc_card *card)
}
md = mmc_blk_alloc(card);
if (IS_ERR(md))
return PTR_ERR(md);
if (IS_ERR(md)) {
ret = PTR_ERR(md);
goto out_free;
}
if (mmc_blk_alloc_parts(card, md))
ret = mmc_blk_alloc_parts(card, md);
if (ret)
goto out;
dev_set_drvdata(&card->dev, md);
if (mmc_add_disk(md))
ret = mmc_add_disk(md);
if (ret)
goto out;
list_for_each_entry(part_md, &md->part, part) {
if (mmc_add_disk(part_md))
ret = mmc_add_disk(part_md);
if (ret)
goto out;
}
@ -2926,10 +2932,12 @@ static int mmc_blk_probe(struct mmc_card *card)
return 0;
out:
out:
mmc_blk_remove_parts(card, md);
mmc_blk_remove_req(md);
return 0;
out_free:
destroy_workqueue(card->complete_wq);
return ret;
}
static void mmc_blk_remove(struct mmc_card *card)