From f1dfc945847c5cb5462ed7f7c8bbf348e196023d Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin Date: Fri, 18 Apr 2025 17:25:12 +0100 Subject: [PATCH] drm/fdinfo: Protect against driver unbind MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 5b1834d6202f86180e451ad1a2a8a193a1da18fc upstream. If we unbind a driver from the PCI device with an active DRM client, subsequent read of the fdinfo data associated with the file descriptor in question will not end well. Protect the path with a drm_dev_enter/exit() pair. Signed-off-by: Tvrtko Ursulin Cc: Christian König Cc: Lucas De Marchi Cc: Rodrigo Vivi Cc: Umesh Nerlige Ramappa Reviewed-by: Christian König Fixes: 3f09a0cd4ea3 ("drm: Add common fdinfo helper") Cc: # v6.5+ Signed-off-by: Christian König Link: https://lore.kernel.org/r/20250418162512.72324-1-tvrtko.ursulin@igalia.com Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/drm_file.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c index ce82c9451dfe..e2cf118ff01d 100644 --- a/drivers/gpu/drm/drm_file.c +++ b/drivers/gpu/drm/drm_file.c @@ -938,6 +938,10 @@ void drm_show_fdinfo(struct seq_file *m, struct file *f) struct drm_file *file = f->private_data; struct drm_device *dev = file->minor->dev; struct drm_printer p = drm_seq_file_printer(m); + int idx; + + if (!drm_dev_enter(dev, &idx)) + return; drm_printf(&p, "drm-driver:\t%s\n", dev->driver->name); drm_printf(&p, "drm-client-id:\t%llu\n", file->client_id); @@ -952,6 +956,8 @@ void drm_show_fdinfo(struct seq_file *m, struct file *f) if (dev->driver->show_fdinfo) dev->driver->show_fdinfo(&p, file); + + drm_dev_exit(idx); } EXPORT_SYMBOL(drm_show_fdinfo);