Patch "i3c: dw: Fix use-after-free in dw_i3c_master driver due to race condition" has been added to the 6.12-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    i3c: dw: Fix use-after-free in dw_i3c_master driver due to race condition

to the 6.12-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     i3c-dw-fix-use-after-free-in-dw_i3c_master-driver-du.patch
and it can be found in the queue-6.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 4f6412cbbdc8bcda2865de22e652d1d06b526fc3
Author: Pei Xiao <xiaopei01@xxxxxxxxxx>
Date:   Wed Nov 27 18:35:11 2024 +0800

    i3c: dw: Fix use-after-free in dw_i3c_master driver due to race condition
    
    [ Upstream commit b75439c945b94dd8a2b645355bdb56f948052601 ]
    
    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: 1dd728f5d4d4 ("i3c: master: Add driver for Synopsys DesignWare IP")
    Signed-off-by: Pei Xiao <xiaopei01@xxxxxxxxxx>
    Acked-by: Mukesh Kumar Savaliya <quic_msavaliy@xxxxxxxxxxx>
    Link: https://lore.kernel.org/r/bfc49c9527be5b513e7ceafeba314ca40a5be4bc.1732703537.git.xiaopei01@xxxxxxxxxx
    Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
index 8d694672c1104..dbcd3984f2578 100644
--- a/drivers/i3c/master/dw-i3c-master.c
+++ b/drivers/i3c/master/dw-i3c-master.c
@@ -1624,6 +1624,7 @@ 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);