--- /dev/null
+From f74a7afc224acd5e922c7a2e52244d891bbe44ee Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Ricardo=20Ca=C3=B1uelo?= <ricardo.canuelo@collabora.com>
+Date: Wed, 30 Aug 2023 12:04:18 +0200
+Subject: usb: hub: Guard against accesses to uninitialized BOS descriptors
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Ricardo Cañuelo <ricardo.canuelo@collabora.com>
+
+commit f74a7afc224acd5e922c7a2e52244d891bbe44ee upstream.
+
+Many functions in drivers/usb/core/hub.c and drivers/usb/core/hub.h
+access fields inside udev->bos without checking if it was allocated and
+initialized. If usb_get_bos_descriptor() fails for whatever
+reason, udev->bos will be NULL and those accesses will result in a
+crash:
+
+BUG: kernel NULL pointer dereference, address: 0000000000000018
+PGD 0 P4D 0
+Oops: 0000 [#1] PREEMPT SMP NOPTI
+CPU: 5 PID: 17818 Comm: kworker/5:1 Tainted: G W 5.15.108-18910-gab0e1cb584e1 #1 <HASH:1f9e 1>
+Hardware name: Google Kindred/Kindred, BIOS Google_Kindred.12672.413.0 02/03/2021
+Workqueue: usb_hub_wq hub_event
+RIP: 0010:hub_port_reset+0x193/0x788
+Code: 89 f7 e8 20 f7 15 00 48 8b 43 08 80 b8 96 03 00 00 03 75 36 0f b7 88 92 03 00 00 81 f9 10 03 00 00 72 27 48 8b 80 a8 03 00 00 <48> 83 78 18 00 74 19 48 89 df 48 8b 75 b0 ba 02 00 00 00 4c 89 e9
+RSP: 0018:ffffab740c53fcf8 EFLAGS: 00010246
+RAX: 0000000000000000 RBX: ffffa1bc5f678000 RCX: 0000000000000310
+RDX: fffffffffffffdff RSI: 0000000000000286 RDI: ffffa1be9655b840
+RBP: ffffab740c53fd70 R08: 00001b7d5edaa20c R09: ffffffffb005e060
+R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
+R13: ffffab740c53fd3e R14: 0000000000000032 R15: 0000000000000000
+FS: 0000000000000000(0000) GS:ffffa1be96540000(0000) knlGS:0000000000000000
+CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
+CR2: 0000000000000018 CR3: 000000022e80c005 CR4: 00000000003706e0
+Call Trace:
+hub_event+0x73f/0x156e
+? hub_activate+0x5b7/0x68f
+process_one_work+0x1a2/0x487
+worker_thread+0x11a/0x288
+kthread+0x13a/0x152
+? process_one_work+0x487/0x487
+? kthread_associate_blkcg+0x70/0x70
+ret_from_fork+0x1f/0x30
+
+Fall back to a default behavior if the BOS descriptor isn't accessible
+and skip all the functionalities that depend on it: LPM support checks,
+Super Speed capabilitiy checks, U1/U2 states setup.
+
+Signed-off-by: Ricardo Cañuelo <ricardo.canuelo@collabora.com>
+Cc: stable <stable@vger.kernel.org>
+Link: https://lore.kernel.org/r/20230830100418.1952143-1-ricardo.canuelo@collabora.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/usb/core/hub.c | 25 ++++++++++++++++++++++---
+ drivers/usb/core/hub.h | 2 +-
+ 2 files changed, 23 insertions(+), 4 deletions(-)
+
+--- a/drivers/usb/core/hub.c
++++ b/drivers/usb/core/hub.c
+@@ -150,6 +150,10 @@ int usb_device_supports_lpm(struct usb_d
+ if (udev->quirks & USB_QUIRK_NO_LPM)
+ return 0;
+
++ /* Skip if the device BOS descriptor couldn't be read */
++ if (!udev->bos)
++ return 0;
++
+ /* USB 2.1 (and greater) devices indicate LPM support through
+ * their USB 2.0 Extended Capabilities BOS descriptor.
+ */
+@@ -326,6 +330,10 @@ static void usb_set_lpm_parameters(struc
+ if (!udev->lpm_capable || udev->speed < USB_SPEED_SUPER)
+ return;
+
++ /* Skip if the device BOS descriptor couldn't be read */
++ if (!udev->bos)
++ return;
++
+ hub = usb_hub_to_struct_hub(udev->parent);
+ /* It doesn't take time to transition the roothub into U0, since it
+ * doesn't have an upstream link.
+@@ -2698,13 +2706,17 @@ out_authorized:
+ static enum usb_ssp_rate get_port_ssp_rate(struct usb_device *hdev,
+ u32 ext_portstatus)
+ {
+- struct usb_ssp_cap_descriptor *ssp_cap = hdev->bos->ssp_cap;
++ struct usb_ssp_cap_descriptor *ssp_cap;
+ u32 attr;
+ u8 speed_id;
+ u8 ssac;
+ u8 lanes;
+ int i;
+
++ if (!hdev->bos)
++ goto out;
++
++ ssp_cap = hdev->bos->ssp_cap;
+ if (!ssp_cap)
+ goto out;
+
+@@ -4186,8 +4198,15 @@ static void usb_enable_link_state(struct
+ enum usb3_link_state state)
+ {
+ int timeout, ret;
+- __u8 u1_mel = udev->bos->ss_cap->bU1devExitLat;
+- __le16 u2_mel = udev->bos->ss_cap->bU2DevExitLat;
++ __u8 u1_mel;
++ __le16 u2_mel;
++
++ /* Skip if the device BOS descriptor couldn't be read */
++ if (!udev->bos)
++ return;
++
++ u1_mel = udev->bos->ss_cap->bU1devExitLat;
++ u2_mel = udev->bos->ss_cap->bU2DevExitLat;
+
+ /* If the device says it doesn't have *any* exit latency to come out of
+ * U1 or U2, it's probably lying. Assume it doesn't implement that link
+--- a/drivers/usb/core/hub.h
++++ b/drivers/usb/core/hub.h
+@@ -141,7 +141,7 @@ static inline int hub_is_superspeedplus(
+ {
+ return (hdev->descriptor.bDeviceProtocol == USB_HUB_PR_SS &&
+ le16_to_cpu(hdev->descriptor.bcdUSB) >= 0x0310 &&
+- hdev->bos->ssp_cap);
++ hdev->bos && hdev->bos->ssp_cap);
+ }
+
+ static inline unsigned hub_power_on_good_delay(struct usb_hub *hub)