The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 6647e6cdba753e71170be7da2acfead7154f56d8 Mon Sep 17 00:00:00 2001
From: Maarten Lankhorst maarten.lankhorst@linux.intel.com Date: Wed, 12 Feb 2020 14:54:45 +0100 Subject: [PATCH] drm/i915: Move cec_notifier to intel_hdmi_connector_unregister, v2.
This fixes the following KASAN splash on module reload: [ 145.136327] ================================================================== [ 145.136502] BUG: KASAN: use-after-free in intel_hdmi_destroy+0x74/0x80 [i915] [ 145.136514] Read of size 8 at addr ffff888216641830 by task kworker/1:1/134
[ 145.136535] CPU: 1 PID: 134 Comm: kworker/1:1 Tainted: G U T 5.5.0-rc7-valkyria+ #5783 [ 145.136539] Hardware name: GIGABYTE GB-BKi3A-7100/MFLP3AP-00, BIOS F1 07/27/2016 [ 145.136546] Workqueue: events drm_connector_free_work_fn [ 145.136551] Call Trace: [ 145.136560] dump_stack+0xa1/0xe0 [ 145.136571] print_address_description.constprop.0+0x1e/0x210 [ 145.136639] ? intel_hdmi_destroy+0x74/0x80 [i915] [ 145.136703] ? intel_hdmi_destroy+0x74/0x80 [i915] [ 145.136710] __kasan_report.cold+0x1b/0x37 [ 145.136790] ? intel_hdmi_destroy+0x74/0x80 [i915] [ 145.136863] ? intel_hdmi_destroy+0x74/0x80 [i915] [ 145.136870] kasan_report+0x27/0x30 [ 145.136881] __asan_report_load8_noabort+0x1c/0x20 [ 145.136946] intel_hdmi_destroy+0x74/0x80 [i915] [ 145.136954] drm_connector_free_work_fn+0xd1/0x100 [ 145.136967] process_one_work+0x86e/0x1610 [ 145.136987] ? pwq_dec_nr_in_flight+0x2f0/0x2f0 [ 145.137004] ? move_linked_works+0x128/0x2c0 [ 145.137021] worker_thread+0x63e/0xc90 [ 145.137048] kthread+0x2f6/0x3f0 [ 145.137054] ? calculate_sigpending+0x81/0xa0 [ 145.137059] ? process_one_work+0x1610/0x1610 [ 145.137064] ? kthread_bind+0x40/0x40 [ 145.137075] ret_from_fork+0x24/0x30
[ 145.137111] Allocated by task 0: [ 145.137119] (stack is not available)
[ 145.137137] Freed by task 5053: [ 145.137147] save_stack+0x28/0x90 [ 145.137152] __kasan_slab_free+0x136/0x180 [ 145.137157] kasan_slab_free+0x26/0x30 [ 145.137161] kfree+0xe6/0x350 [ 145.137242] intel_ddi_encoder_destroy+0x60/0x80 [i915] [ 145.137252] drm_mode_config_cleanup+0x11d/0x8f0 [ 145.137329] intel_modeset_driver_remove+0x1f5/0x350 [i915] [ 145.137403] i915_driver_remove+0xc4/0x130 [i915] [ 145.137482] i915_pci_remove+0x3e/0x90 [i915] [ 145.137489] pci_device_remove+0x108/0x2d0 [ 145.137494] device_release_driver_internal+0x1e6/0x4a0 [ 145.137499] driver_detach+0xcb/0x198 [ 145.137503] bus_remove_driver+0xde/0x204 [ 145.137508] driver_unregister+0x6d/0xa0 [ 145.137513] pci_unregister_driver+0x2e/0x230 [ 145.137576] i915_exit+0x1f/0x26 [i915] [ 145.137157] kasan_slab_free+0x26/0x30 [ 145.137161] kfree+0xe6/0x350 [ 145.137242] intel_ddi_encoder_destroy+0x60/0x80 [i915] [ 145.137252] drm_mode_config_cleanup+0x11d/0x8f0 [ 145.137329] intel_modeset_driver_remove+0x1f5/0x350 [i915] [ 145.137403] i915_driver_remove+0xc4/0x130 [i915] [ 145.137482] i915_pci_remove+0x3e/0x90 [i915] [ 145.137489] pci_device_remove+0x108/0x2d0 [ 145.137494] device_release_driver_internal+0x1e6/0x4a0 [ 145.137499] driver_detach+0xcb/0x198 [ 145.137503] bus_remove_driver+0xde/0x204 [ 145.137508] driver_unregister+0x6d/0xa0 [ 145.137513] pci_unregister_driver+0x2e/0x230 [ 145.137576] i915_exit+0x1f/0x26 [i915] [ 145.137581] __x64_sys_delete_module+0x35b/0x470 [ 145.137586] do_syscall_64+0x99/0x4e0 [ 145.137591] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 145.137606] The buggy address belongs to the object at ffff888216640000 which belongs to the cache kmalloc-8k of size 8192 [ 145.137618] The buggy address is located 6192 bytes inside of 8192-byte region [ffff888216640000, ffff888216642000) [ 145.137630] The buggy address belongs to the page: [ 145.137640] page:ffffea0008599000 refcount:1 mapcount:0 mapping:ffff888107c02a80 index:0xffff888216644000 compound_mapcount: 0 [ 145.137647] raw: 0200000000010200 0000000000000000 0000000100000001 ffff888107c02a80 [ 145.137652] raw: ffff888216644000 0000000080020001 00000001ffffffff 0000000000000000 [ 145.137656] page dumped because: kasan: bad access detected
[ 145.137668] Memory state around the buggy address: [ 145.137678] ffff888216641700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 145.137687] ffff888216641780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 145.137697] >ffff888216641800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 145.137706] ^ [ 145.137715] ffff888216641880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 145.137724] ffff888216641900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 145.137733] ================================================================== [ 145.137742] Disabling lock debugging due to kernel taint
Changes since v1: - Add fixes tags. - Use early unregister.
Signed-off-by: Maarten Lankhorst maarten.lankhorst@linux.intel.com Fixes: 9c229127aee2 ("drm/i915: hdmi: add CEC notifier to intel_hdmi") Cc: stable@vger.kernel.org # v4.19+ Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch Link: https://patchwork.freedesktop.org/patch/msgid/20200212135445.1469133-1-maart... (cherry picked from commit a581483b1e5466d28fc50ff623fba31cea2cccb6) Signed-off-by: Jani Nikula jani.nikula@intel.com
diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c index 010f37240710..95b6d9457910 100644 --- a/drivers/gpu/drm/i915/display/intel_hdmi.c +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c @@ -2867,19 +2867,13 @@ intel_hdmi_connector_register(struct drm_connector *connector) return ret; }
-static void intel_hdmi_destroy(struct drm_connector *connector) +static void intel_hdmi_connector_unregister(struct drm_connector *connector) { struct cec_notifier *n = intel_attached_hdmi(to_intel_connector(connector))->cec_notifier;
cec_notifier_conn_unregister(n);
- intel_connector_destroy(connector); -} - -static void intel_hdmi_connector_unregister(struct drm_connector *connector) -{ intel_hdmi_remove_i2c_symlink(connector); - intel_connector_unregister(connector); }
@@ -2891,7 +2885,7 @@ static const struct drm_connector_funcs intel_hdmi_connector_funcs = { .atomic_set_property = intel_digital_connector_atomic_set_property, .late_register = intel_hdmi_connector_register, .early_unregister = intel_hdmi_connector_unregister, - .destroy = intel_hdmi_destroy, + .destroy = intel_connector_destroy, .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, .atomic_duplicate_state = intel_digital_connector_duplicate_state, };