6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Duoming Zhou [ Upstream commit ab58153ec64fa3fc9aea09ca09dc9322e0b54a7c ] The delayed work item 'imm_tq' is initialized in imm_attach() and scheduled via imm_queuecommand() for processing SCSI commands. When the IMM parallel port SCSI host adapter is detached through imm_detach(), the imm_struct device instance is deallocated. However, the delayed work might still be pending or executing when imm_detach() is called, leading to use-after-free bugs when the work function imm_interrupt() accesses the already freed imm_struct memory. The race condition can occur as follows: CPU 0(detach thread) | CPU 1 | imm_queuecommand() | imm_queuecommand_lck() imm_detach() | schedule_delayed_work() kfree(dev) //FREE | imm_interrupt() | dev = container_of(...) //USE dev-> //USE Add disable_delayed_work_sync() in imm_detach() to guarantee proper cancellation of the delayed work item before imm_struct is deallocated. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Duoming Zhou Link: https://patch.msgid.link/20251028100149.40721-1-duoming@zju.edu.cn Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/imm.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/scsi/imm.c b/drivers/scsi/imm.c index 07db98161a036..dbe0598ce4bf4 100644 --- a/drivers/scsi/imm.c +++ b/drivers/scsi/imm.c @@ -1269,6 +1269,7 @@ static void imm_detach(struct parport *pb) if (dev->dev->port == pb) { list_del_init(&dev->list); scsi_remove_host(dev->host); + cancel_delayed_work_sync(&dev->imm_tq); scsi_host_put(dev->host); parport_unregister_device(dev->dev); kfree(dev); -- 2.53.0