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i3c: dw: Fix use-after-free in dw_i3c_master driver due to race condi…
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…tion

In dw_i3c_common_probe, &master->hj_work is bound with
dw_i3c_hj_work. And dw_i3c_master_irq_handler can call
dw_i3c_master_irq_handle_ibis function to start the work.

If we remove the module which will call dw_i3c_common_remove to
make cleanup, it will free master->base through i3c_master_unregister
while the work mentioned above will be used. The sequence of operations
that may lead to a UAF bug is as follows:

CPU0                                      CPU1

                                     | dw_i3c_hj_work
dw_i3c_common_remove                 |
i3c_master_unregister(&master->base) |
device_unregister(&master->dev)      |
device_release                       |
//free master->base                  |
                                     | i3c_master_do_daa(&master->base)
                                     | //use master->base

Fix it by ensuring that the work is canceled before proceeding with
the cleanup in dw_i3c_common_remove.

Fixes: 1dd728f ("i3c: master: Add driver for Synopsys DesignWare IP")
Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn>
Acked-by: Mukesh Kumar Savaliya <quic_msavaliy@quicinc.com>
Link: https://lore.kernel.org/r/bfc49c9527be5b513e7ceafeba314ca40a5be4bc.1732703537.git.xiaopei01@kylinos.cn
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
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Pei Xiao authored and Alexandre Belloni committed Jan 12, 2025
1 parent 40384c8 commit b75439c
Showing 1 changed file with 1 addition and 0 deletions.
1 change: 1 addition & 0 deletions drivers/i3c/master/dw-i3c-master.c
Original file line number Diff line number Diff line change
Expand Up @@ -1647,6 +1647,7 @@ EXPORT_SYMBOL_GPL(dw_i3c_common_probe);

void dw_i3c_common_remove(struct dw_i3c_master *master)
{
cancel_work_sync(&master->hj_work);
i3c_master_unregister(&master->base);

pm_runtime_disable(master->dev);
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