4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ricardo Cañuelo <ricardo.canuelo@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20230830100418.1952143-1-ricardo.canuelo@xxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/core/hub.c | 28 ++++++++++++++++++++++++---- drivers/usb/core/hub.h | 2 +- 2 files changed, 25 insertions(+), 5 deletions(-) --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -147,6 +147,10 @@ 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. */ @@ -323,6 +327,10 @@ 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. @@ -2644,7 +2652,8 @@ out_authorized: } /* - * Return 1 if port speed is SuperSpeedPlus, 0 otherwise + * Return 1 if port speed is SuperSpeedPlus, 0 otherwise or if the + * capability couldn't be checked. * check it from the link protocol field of the current speed ID attribute. * current speed ID is got from ext port status request. Sublink speed attribute * table is returned with the hub BOS SSP device capability descriptor @@ -2654,8 +2663,12 @@ static int port_speed_is_ssp(struct usb_ int ssa_count; u32 ss_attr; int i; - struct usb_ssp_cap_descriptor *ssp_cap = hdev->bos->ssp_cap; + struct usb_ssp_cap_descriptor *ssp_cap; + if (!hdev->bos) + return 0; + + ssp_cap = hdev->bos->ssp_cap; if (!ssp_cap) return 0; @@ -4057,8 +4070,15 @@ 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 @@ -139,7 +139,7 @@ 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)
