Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: Fix slab-use-after-free in hdcp

The HDCP code in amdgpu_dm_hdcp.c copies pointers to amdgpu_dm_connector objects without incrementing the kref reference counts. When using a USB-C dock, and the dock is unplugged, the corresponding amdgpu_dm_connector objects are freed, creating dangling pointers in the HDCP code. When the dock is plugged back, the dangling pointers are dereferenced, resulting in a slab-use-after-free:

[ 66.775837] BUG: KASAN: slab-use-after-free in event_property_validate+0x42f/0x6c0 [amdgpu] [ 66.776171] Read of size 4 at addr ffff888127804120 by task kworker/0:1/10

[ 66.776179] CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.14.0-rc7-00180-g54505f727a38-dirty #233 [ 66.776183] Hardware name: HP HP Pavilion Aero Laptop 13-be0xxx/8916, BIOS F.17 12/18/2024 [ 66.776186] Workqueue: events event_property_validate [amdgpu] [ 66.776494] Call Trace: [ 66.776496] <TASK> [ 66.776497] dump_stack_lvl+0x70/0xa0 [ 66.776504] print_report+0x175/0x555 [ 66.776507] ? __virt_addr_valid+0x243/0x450 [ 66.776510] ? kasan_complete_mode_report_info+0x66/0x1c0 [ 66.776515] kasan_report+0xeb/0x1c0 [ 66.776518] ? event_property_validate+0x42f/0x6c0 [amdgpu] [ 66.776819] ? event_property_validate+0x42f/0x6c0 [amdgpu] [ 66.777121] __asan_report_load4_noabort+0x14/0x20 [ 66.777124] event_property_validate+0x42f/0x6c0 [amdgpu] [ 66.777342] ? __lock…