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ASoC: meson: Keep link pointers valid on realloc failure

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meson_card_reallocate_links() grows the DAI link and private data
arrays with two consecutive krealloc() calls and updates the owner
pointers only after both calls have succeeded.

A successful krealloc() may move the data: it frees the old block and
returns a new one. When that happens for the link array and the second
krealloc() then fails, card->dai_link still points to the block that
krealloc() already freed, and the error path frees the new block too.
The probe error path then calls meson_card_clean_references(), which
dereferences card->dai_link and kfree()s it again, resulting in a
use-after-free and a double free.

Commit card->dai_link and card->num_links right after the first
krealloc() succeeds, so the pointer always refers to a valid allocation
that meson_card_clean_references() can walk and free. krealloc() with
__GFP_ZERO zero-initializes the added entries, so walking them on the
error path is safe. With both failure paths reduced to a plain return,
drop the goto labels and the error message.

Fixes: 7864a79f37 ("ASoC: meson: add axg sound card support")
Signed-off-by: Linmao Li <lilinmao@kylinos.cn>
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://patch.msgid.link/20260717012433.1432285-1-lilinmao@kylinos.cn
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Linmao Li 2026-07-17 09:24:33 +08:00 committed by Mark Brown
parent c89b22faa9
commit 2aaa41cf97
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 6 additions and 11 deletions
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17
sound/soc/meson/meson-card-utils.c
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@ -50,25 +50,20 @@ int meson_card_reallocate_links(struct snd_soc_card *card,
num_links * sizeof(*priv->card.dai_link),
GFP_KERNEL | __GFP_ZERO);
if (!links)
goto err_links;
return -ENOMEM;
priv->card.dai_link = links;
priv->card.num_links = num_links;
ldata = krealloc(priv->link_data,
num_links * sizeof(*priv->link_data),
GFP_KERNEL | __GFP_ZERO);
/* meson_card_clean_references() will free the links on this error path */
if (!ldata)
goto err_ldata;
return -ENOMEM;
priv->card.dai_link = links;
priv->link_data = ldata;
priv->card.num_links = num_links;
return 0;
err_ldata:
kfree(links);
err_links:
dev_err(priv->card.dev, "failed to allocate links\n");
return -ENOMEM;
}
EXPORT_SYMBOL_GPL(meson_card_reallocate_links);