ASoC: soc-core: flush delayed work before removing DAIs and widgets

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[ Upstream commit 95bc5c2255 ]

When a sound card is unbound while a PCM stream is open, a
use-after-free can occur in snd_soc_dapm_stream_event(), called from
the close_delayed_work workqueue handler.

During unbind, snd_soc_unbind_card() flushes delayed work and then
calls soc_cleanup_card_resources(). Inside cleanup,
snd_card_disconnect_sync() releases all PCM file descriptors, and
the resulting PCM close path can call snd_soc_dapm_stream_stop()
which schedules new delayed work with a pmdown_time timer delay.
Since this happens after the flush in snd_soc_unbind_card(), the
new work is not caught. soc_remove_link_components() then frees
DAPM widgets before this work fires, leading to the use-after-free.

The existing flush in soc_free_pcm_runtime() also cannot help as it
runs after soc_remove_link_components() has already freed the widgets.

Add a flush in soc_cleanup_card_resources() after
snd_card_disconnect_sync() (after which no new PCM closes can
schedule further delayed work) and before soc_remove_link_dais()
and soc_remove_link_components() (which tear down the structures the
delayed work accesses).

Fixes: e894efef9a ("ASoC: core: add support to card rebind")
Signed-off-by: Matteo Cotifava <cotifavamatteo@gmail.com>
Link: https://patch.msgid.link/20260309215412.545628-3-cotifavamatteo@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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matteo.cotifava 2026-03-09 22:54:12 +01:00 • committed by Greg Kroah-Hartman

parent a4aa08c820

commit 7d33e61409

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sound/soc/soc-core.c

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