git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From 609366e7a06d035990df78f1562291c3bf0d4a12 Mon Sep 17 00:00:00 2001
   2 From: Kaixin Wang <kxwang23@m.fudan.edu.cn>
   3 Date: Wed, 11 Sep 2024 23:35:44 +0800
   4 Subject: i3c: master: cdns: Fix use after free vulnerability in cdns_i3c_master Driver Due to Race Condition
   5
   6 From: Kaixin Wang <kxwang23@m.fudan.edu.cn>
   7
   8 commit 609366e7a06d035990df78f1562291c3bf0d4a12 upstream.
   9
  10 In the cdns_i3c_master_probe function, &master->hj_work is bound with
  11 cdns_i3c_master_hj. And cdns_i3c_master_interrupt can call
  12 cnds_i3c_master_demux_ibis function to start the work.
  13
  14 If we remove the module which will call cdns_i3c_master_remove to
  15 make cleanup, it will free master->base through i3c_master_unregister
  16 while the work mentioned above will be used. The sequence of operations
  17 that may lead to a UAF bug is as follows:
  18
  19 CPU0                                      CPU1
  20
  21                                      | cdns_i3c_master_hj
  22 cdns_i3c_master_remove               |
  23 i3c_master_unregister(&master->base) |
  24 device_unregister(&master->dev)      |
  25 device_release                       |
  26 //free master->base                  |
  27                                      | i3c_master_do_daa(&master->base)
  28                                      | //use master->base
  29
  30 Fix it by ensuring that the work is canceled before proceeding with
  31 the cleanup in cdns_i3c_master_remove.
  32
  33 Signed-off-by: Kaixin Wang <kxwang23@m.fudan.edu.cn>
  34 Link: https://lore.kernel.org/r/20240911153544.848398-1-kxwang23@m.fudan.edu.cn
  35 Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
  36 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  37 ---
  38  drivers/i3c/master/i3c-master-cdns.c |    1 +
  39  1 file changed, 1 insertion(+)
  40
  41 --- a/drivers/i3c/master/i3c-master-cdns.c
  42 +++ b/drivers/i3c/master/i3c-master-cdns.c
  43 @@ -1667,6 +1667,7 @@ static int cdns_i3c_master_remove(struct
  44  {
  45         struct cdns_i3c_master *master = platform_get_drvdata(pdev);
  46
  47 +       cancel_work_sync(&master->hj_work);
  48         i3c_master_unregister(&master->base);
  49
  50         clk_disable_unprepare(master->sysclk);