5.4-stable review patch. If anyone has any objections, please let me know.
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From: Kaixin Wang kxwang23@m.fudan.edu.cn
commit e3f88665a78045fe35c7669d2926b8d97b892c11 upstream.
In the ssi_protocol_probe() function, &ssi->work is bound with ssip_xmit_work(), In ssip_pn_setup(), the ssip_pn_xmit() function within the ssip_pn_ops structure is capable of starting the work.
If we remove the module which will call ssi_protocol_remove() to make a cleanup, it will free ssi through kfree(ssi), while the work mentioned above will be used. The sequence of operations that may lead to a UAF bug is as follows:
CPU0 CPU1
| ssip_xmit_work ssi_protocol_remove | kfree(ssi); | | struct hsi_client *cl = ssi->cl; | // use ssi
Fix it by ensuring that the work is canceled before proceeding with the cleanup in ssi_protocol_remove().
Signed-off-by: Kaixin Wang kxwang23@m.fudan.edu.cn Acked-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Link: https://lore.kernel.org/r/20240918120749.1730-1-kxwang23@m.fudan.edu.cn Signed-off-by: Sebastian Reichel sebastian.reichel@collabora.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/hsi/clients/ssi_protocol.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/hsi/clients/ssi_protocol.c +++ b/drivers/hsi/clients/ssi_protocol.c @@ -403,6 +403,7 @@ static void ssip_reset(struct hsi_client del_timer(&ssi->rx_wd); del_timer(&ssi->tx_wd); del_timer(&ssi->keep_alive); + cancel_work_sync(&ssi->work); ssi->main_state = 0; ssi->send_state = 0; ssi->recv_state = 0;