Older platforms and Virtual platforms which doesn't have support for bluetooth device in ACPI firmware will not have valid ACPI handle. Check for validity of handle before accessing. dmesg log from simics environment (virtual platform): BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 IP: acpi_ns_walk_namespace+0x5c/0x278 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI Modules linked in: bnep intel_powerclamp coretemp kvm_intel kvm irqbypass intel_cstate input_leds joydev serio_raw mac_hid btusb(OE) btintel(OE) bluetooth(OE) lpc_ich compat(OE) ecdh_generic i7core_edac i5500_temp shpchp binfmt_misc sch_fq_codel parport_pc ppdev lp parport ip_tables x_tables autofs4 hid_generic usbhid hid e1000e psmouse ahci pata_acpi libahci ptp pps_core floppy CPU: 0 PID: 35 Comm: kworker/u3:0 Tainted: G OE 4.15.0-140-generic #144-Ubuntu Hardware name: Simics Simics, BIOS Simics 01/01/2011 Workqueue: hci0 hci_power_on [bluetooth] RIP: 0010:acpi_ns_walk_namespace+0x5c/0x278 RSP: 0000:ffffaa9c0049bba8 EFLAGS: 00010246 RAX: 0000000000000001 RBX: 0000000000001001 RCX: 0000000000000010 RDX: ffffffff92ea7e27 RSI: ffffffff92ea7e10 RDI: 00000000000000c8 RBP: ffffaa9c0049bbf8 R08: 0000000000000000 R09: ffffffffc05b39d0 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 R13: 0000000000000000 R14: ffffffffc05b39d0 R15: ffffaa9c0049bc70 FS: 0000000000000000(0000) GS:ffff8be73fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000018 CR3: 0000000075f0e000 CR4: 00000000000006f0 Fixes: ee9b749cb9ad ("Bluetooth: btintel: Iterate only bluetooth device ACPI entries") Signed-off-by: Kiran K <kiran.k@xxxxxxxxx> --- drivers/bluetooth/btintel.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/bluetooth/btintel.c b/drivers/bluetooth/btintel.c index e8d4b59e89c5..af774688f1c0 100644 --- a/drivers/bluetooth/btintel.c +++ b/drivers/bluetooth/btintel.c @@ -2326,6 +2326,7 @@ static void btintel_set_ppag(struct hci_dev *hdev, struct intel_version_tlv *ver struct btintel_ppag ppag; struct sk_buff *skb; struct btintel_loc_aware_reg ppag_cmd; + acpi_handle handle; /* PPAG is not supported if CRF is HrP2, Jfp2, JfP1 */ switch (ver->cnvr_top & 0xFFF) { @@ -2335,12 +2336,18 @@ static void btintel_set_ppag(struct hci_dev *hdev, struct intel_version_tlv *ver return; } + handle = ACPI_HANDLE(GET_HCIDEV_DEV(hdev)); + if (!handle) { + bt_dev_info(hdev, "No support for BT device in ACPI firmware"); + return; + } + memset(&ppag, 0, sizeof(ppag)); ppag.hdev = hdev; ppag.status = AE_NOT_FOUND; - acpi_walk_namespace(ACPI_TYPE_PACKAGE, ACPI_HANDLE(GET_HCIDEV_DEV(hdev)), - 1, NULL, btintel_ppag_callback, &ppag, NULL); + acpi_walk_namespace(ACPI_TYPE_PACKAGE, handle, 1, NULL, + btintel_ppag_callback, &ppag, NULL); if (ACPI_FAILURE(ppag.status)) { if (ppag.status == AE_NOT_FOUND) { -- 2.17.1