usb: usbtmc: Flush anchored URBs in usbtmc_release

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>

diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index d39bbfd7fd18a91b24237cd99b881c36a5e4cc98..bd9347804dec6d37c8ebea6f2852127b4e003338 100644 (file)
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -254,6 +254,9 @@ static int usbtmc_release(struct inode *inode, struct file *file)
        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);