[PATCH 5.15 468/570] usb: usbtmc: Flush anchored URBs in usbtmc_release

Greg Kroah-Hartman
2026-04-13T16:38:15Z

From: Heitor Alves de Siqueira <halves@igalia.com>

commit 8a768552f7a8276fb9e01d49773d2094ace7c8f1 upstream.

When calling usbtmc_release, pending anchored URBs must be flushed or
killed to prevent use-after-free errors (e.g. in the HCD giveback
path). Call usbtmc_draw_down() to allow anchored URBs to be completed.

Fixes: 4f3c8d6eddc2 ("usb: usbtmc: Support Read Status Byte with SRQ per file")
Reported-by: syzbot+9a3c54f52bd1edbd975f@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=9a3c54f52bd1edbd975f
Cc: stable <stable@kernel.org>
Signed-off-by: Heitor Alves de Siqueira <halves@igalia.com>
Link: https://patch.msgid.link/20260312-usbtmc-flush-release-v1-1-5755e9f4336f@igalia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/class/usbtmc.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -254,6 +254,9 @@ static int usbtmc_release(struct inode *
list_del(&file_data->file_elem);

spin_unlock_irq(&file_data->data->dev_lock);
+
+ /* flush anchored URBs */
+ usbtmc_draw_down(file_data);
mutex_unlock(&file_data->data->io_mutex);

kref_put(&file_data->data->kref, usbtmc_delete);