From 4ffee1aebb0c0ffcda9faffd17834ea9b00d42cc Mon Sep 17 00:00:00 2001 From: Myeonghun Pak Date: Mon, 27 Jul 2026 21:34:14 +0900 Subject: [PATCH] usb: storage: realtek_cr: fix use-after-free on disconnect realtek_cr_destructor() calls timer_delete() before the chip containing the timer is freed. The timer callback may still be running and can rearm itself, resulting in a use-after-free. Use timer_shutdown_sync() to wait for the callback and prevent further rearming. Do this unconditionally because ss_en may be changed after the timer is armed. Move timer_setup() into init_realtek_cr() so the timer is initialized before any failure path can invoke the destructor. Found by static analysis. Fixes: e931830bb877 ("Realtek cr: Add autosuspend function.") Cc: stable Co-developed-by: Ijae Kim Signed-off-by: Ijae Kim Signed-off-by: Myeonghun Pak Link: https://patch.msgid.link/20260727123414.44700-1-mhun512@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/storage/realtek_cr.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/usb/storage/realtek_cr.c b/drivers/usb/storage/realtek_cr.c index af038b897c6b..c4b28744693b 100644 --- a/drivers/usb/storage/realtek_cr.c +++ b/drivers/usb/storage/realtek_cr.c @@ -916,7 +916,6 @@ static int realtek_cr_autosuspend_setup(struct us_data *us) us->proto_handler = rts51x_invoke_transport; chip->timer_expires = 0; - timer_setup(&chip->rts51x_suspend_timer, rts51x_suspend_timer_fn, 0); fw5895_init(us); /* enable autosuspend function of the usb device */ @@ -934,10 +933,7 @@ static void realtek_cr_destructor(void *extra) return; #ifdef CONFIG_REALTEK_AUTOPM - if (ss_en) { - timer_delete(&chip->rts51x_suspend_timer); - chip->timer_expires = 0; - } + timer_shutdown_sync(&chip->rts51x_suspend_timer); #endif kfree(chip->status); } @@ -982,6 +978,9 @@ static int init_realtek_cr(struct us_data *us) us->extra = chip; us->extra_destructor = realtek_cr_destructor; +#ifdef CONFIG_REALTEK_AUTOPM + timer_setup(&chip->rts51x_suspend_timer, rts51x_suspend_timer_fn, 0); +#endif us->max_lun = chip->max_lun = rts51x_get_max_lun(us); chip->us = us;