Lukasz Majczak 6c668e2f33 drm/dp_mst: Fix NULL deref in get_mst_branch_device_by_guid_helper() ... commit 3d887d5124 upstream. As drm_dp_get_mst_branch_device_by_guid() is called from drm_dp_get_mst_branch_device_by_guid(), mstb parameter has to be checked, otherwise NULL dereference may occur in the call to the memcpy() and cause following: [12579.365869] BUG: kernel NULL pointer dereference, address: 0000000000000049 [12579.365878] #PF: supervisor read access in kernel mode [12579.365880] #PF: error_code(0x0000) - not-present page [12579.365882] PGD 0 P4D 0 [12579.365887] Oops: 0000 [#1] PREEMPT SMP NOPTI ... [12579.365895] Workqueue: events_long drm_dp_mst_up_req_work [12579.365899] RIP: 0010:memcmp+0xb/0x29 [12579.365921] Call Trace: [12579.365927] get_mst_branch_device_by_guid_helper+0x22/0x64 [12579.365930] drm_dp_mst_up_req_work+0x137/0x416 [12579.365933] process_one_work+0x1d0/0x419 [12579.365935] worker_thread+0x11a/0x289 [12579.365938] kthread+0x13e/0x14f [12579.365941] ? process_one_work+0x419/0x419 [12579.365943] ? kthread_blkcg+0x31/0x31 [12579.365946] ret_from_fork+0x1f/0x30 As get_mst_branch_device_by_guid_helper() is recursive, moving condition to the first line allow to remove a similar one for step over of NULL elements inside a loop. Fixes: 5e93b8208d ("drm/dp/mst: move GUID storage from mgr, port to only mst branch") Cc: <stable@vger.kernel.org> # 4.14+ Signed-off-by: Lukasz Majczak <lma@semihalf.com> Reviewed-by: Radoslaw Biernacki <rad@chromium.org> Signed-off-by: Manasi Navare <navaremanasi@chromium.org> Link: https://patchwork.freedesktop.org/patch/msgid/20230922063410.23626-1-lma@semihalf.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2023-11-02 09:35:25 +01:00
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Kconfig	drm/display: Fix build error without CONFIG_OF	2022-06-23 16:18:02 +02:00
Makefile	…
drm_display_helper_mod.c	…
drm_dp_aux_bus.c	…
drm_dp_aux_dev.c	…
drm_dp_cec.c	…
drm_dp_dual_mode_helper.c	drm/display: Don't assume dual mode adaptors support i2c sub-addressing	2022-11-15 23:31:02 +02:00
drm_dp_helper.c	Driver core changes for 6.1-rc1	2022-10-07 17:04:10 -07:00
drm_dp_helper_internal.h	…
drm_dp_mst_topology.c	drm/dp_mst: Fix NULL deref in get_mst_branch_device_by_guid_helper()	2023-11-02 09:35:25 +01:00
drm_dp_mst_topology_internal.h	…
drm_dsc_helper.c	…
drm_hdcp_helper.c	…
drm_hdmi_helper.c	drm/display: Don't block HDR_OUTPUT_METADATA on unknown EOTF	2023-03-17 08:50:15 +01:00
drm_scdc_helper.c	drm/scdc: Document hotplug gotchas	2022-09-13 16:25:00 +01:00