On Wed, Aug 02, 2023 at 10:43:49AM -0700, cujomalainey@chromium.org wrote:
From: Curtis Malainey cujomalainey@chromium.org
The current implementation of how devices are released is valid for production use cases (root control of memory is handled by card_dev, all other devices are no-ops).
This model does not work though in a kernel hacking environment where KASAN and delayed release on kobj is enabled. If the card_dev device is released before any of the child objects a use-after-free bug is caught by KASAN as the delayed release still has a reference to the devices that were freed by the card_dev release. Also both snd_card and snd_pcm both own two devices internally, so even if they released independently, the shared struct would result in another use after free.
Solution is to move the child devices into their own memory so they can be handled independently and released on their own schedule.
Signed-off-by: Curtis Malainey cujomalainey@chromium.org Cc: Doug Anderson dianders@chromium.org
include/sound/core.h | 2 +- include/sound/pcm.h | 2 +- sound/aoa/soundbus/i2sbus/pcm.c | 4 ++-- sound/core/control.c | 21 +++++++++++++++------ sound/core/control_led.c | 4 ++-- sound/core/pcm.c | 30 ++++++++++++++++++++---------- sound/usb/media.c | 4 ++-- 7 files changed, 43 insertions(+), 24 deletions(-)
Hi,
This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him a patch that has triggered this response. He used to manually respond to these common problems, but in order to save his sanity (he kept writing the same thing over and over, yet to different people), I was created. Hopefully you will not take offence and will fix the problem in your patch and resubmit it so that it can be accepted into the Linux kernel tree.
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