In the Linux kernel, the following vulnerability has been resolved: HID: uclogic: Fix user-memory-access bug in uclogic_params_ugee_v2_init_event_hooks() When CONFIG_HID_UCLOGIC=y and CONFIG_KUNIT_ALL_TESTS=y, launch kernel and then the below user-memory-access bug occurs. In hid_test_uclogic_params_cleanup_event_hooks(),it call uclogic_params_ugee_v2_init_event_hooks() with the first arg=NULL, so when it calls uclogic_params_ugee_v2_has_battery(), the hid_get_drvdata() will access hdev->dev with hdev=NULL, which will cause below user-memory-access. So add a fake_device with quirks member and call hid_set_drvdata() to assign hdev->dev->driver_data which avoids the null-ptr-def bug for drvdata->quirks in uclogic_params_ugee_v2_has_battery(). After applying this patch, the below user-memory-access bug never occurs. general protection fault, probably for non-canonical address 0xdffffc0000000329: 0000 [#1] PREEMPT SMP KASAN KASAN: probably user-memory-access in range [0x0000000000001948-0x000000000000194f] CPU: 5 PID: 2189 Comm: kunit_try_catch Tainted: G B W N 6.6.0-rc2+ #30 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:uclogic_params_ugee_v2_init_event_hooks+0x87/0x600 Code: f3 f3 65 48 8b 14 25 28 00 00 00 48 89 54 24 60 31 d2 48 89 fa c7 44 24 30 00 00 00 00 48 c7 44 24 28 02 f8 02 01 48 c1 ea 03 <80> 3c 02 00 0f 85 2c 04 00 00 48 8b 9d 48 19 00 00 48 b8 00 00 00 RSP: 0000:ffff88810679fc88 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000004 RCX: 0000000000000000 RDX: 0000000000000329 RSI: ffff88810679fd88 RDI: 0000000000001948 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffed1020f639f0 R10: ffff888107b1cf87 R11: 0000000000000400 R12: 1ffff11020cf3f92 R13: ffff88810679fd88 R14: ffff888100b97b08 R15: ffff8881030bb080 FS: 0000000000000000(0000) GS:ffff888119e80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000005286001 CR4: 0000000000770ee0 DR0: ffffffff8fdd6cf4 DR1: ffffffff8fdd6cf5 DR2: ffffffff8fdd6cf6 DR3: ffffffff8fdd6cf7 DR6: 00000000fffe0ff0 DR7: 0000000000000600 PKRU: 55555554 Call Trace: <TASK> ? die_addr+0x3d/0xa0 ? exc_general_protection+0x144/0x220 ? asm_exc_general_protection+0x22/0x30 ? uclogic_params_ugee_v2_init_event_hooks+0x87/0x600 ? sched_clock_cpu+0x69/0x550 ? uclogic_parse_ugee_v2_desc_gen_params+0x70/0x70 ? load_balance+0x2950/0x2950 ? rcu_trc_cmpxchg_need_qs+0x67/0xa0 hid_test_uclogic_params_cleanup_event_hooks+0x9e/0x1a0 ? uclogic_params_ugee_v2_init_event_hooks+0x600/0x600 ? __switch_to+0x5cf/0xe60 ? migrate_enable+0x260/0x260 ? __kthread_parkme+0x83/0x150 ? kunit_try_run_case_cleanup+0xe0/0xe0 kunit_generic_run_threadfn_adapter+0x4a/0x90 ? kunit_try_catch_throw+0x80/0x80 kthread+0x2b5/0x380 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x2d/0x70 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork_asm+0x11/0x20 </TASK> Modules linked in: Dumping ftrace buffer: (ftrace buffer empty) ---[ end trace 0000000000000000 ]--- RIP: 0010:uclogic_params_ugee_v2_init_event_hooks+0x87/0x600 Code: f3 f3 65 48 8b 14 25 28 00 00 00 48 89 54 24 60 31 d2 48 89 fa c7 44 24 30 00 00 00 00 48 c7 44 24 28 02 f8 02 01 48 c1 ea 03 <80> 3c 02 00 0f 85 2c 04 00 00 48 8b 9d 48 19 00 00 48 b8 00 00 00 RSP: 0000:ffff88810679fc88 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000004 RCX: 0000000000000000 RDX: 0000000000000329 RSI: ffff88810679fd88 RDI: 0000000000001948 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffed1020f639f0 R10: ffff888107b1cf87 R11: 0000000000000400 R12: 1ffff11020cf3f92 R13: ffff88810679fd88 R14: ffff888100b97b08 R15: ffff8881030bb080 FS: 0000000000000000(0000) GS:ffff888119e80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000005286001 CR4: 0000000000770ee0 DR0: ffffffff8fdd6cf4 DR1: ---truncated---