6.6-stable review patch. If anyone has any objections, please let me know.
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From: Tvrtko Ursulin tvrtko.ursulin@igalia.com
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 tvrtko.ursulin@igalia.com Cc: Christian König christian.koenig@amd.com Cc: Lucas De Marchi lucas.demarchi@intel.com Cc: Rodrigo Vivi rodrigo.vivi@intel.com Cc: Umesh Nerlige Ramappa umesh.nerlige.ramappa@intel.com Reviewed-by: Christian König christian.koenig@amd.com Fixes: 3f09a0cd4ea3 ("drm: Add common fdinfo helper") Cc: stable@vger.kernel.org # v6.5+ Signed-off-by: Christian König christian.koenig@amd.com Link: https://lore.kernel.org/r/20250418162512.72324-1-tvrtko.ursulin@igalia.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/drm_file.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/drivers/gpu/drm/drm_file.c +++ b/drivers/gpu/drm/drm_file.c @@ -1015,6 +1015,10 @@ void drm_show_fdinfo(struct seq_file *m, 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); @@ -1029,6 +1033,8 @@ void drm_show_fdinfo(struct seq_file *m,
if (dev->driver->show_fdinfo) dev->driver->show_fdinfo(&p, file); + + drm_dev_exit(idx); } EXPORT_SYMBOL(drm_show_fdinfo);