title: usb: hub: Guard against accesses to uninitialized BOS descriptors
description: In the Linux kernel, the following vulnerability has been resolved:
usb: hub: Guard against accesses to uninitialized BOS descriptors
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.
affected:
{
product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 1da177e4c3f4, lessThan: c64e4dca9aef, status: affected, versionType: git
version: 1da177e4c3f4, lessThan: 8e7346bfea56, status: affected, versionType: git
version: 1da177e4c3f4, lessThan: 6ad3e9fd3632, status: affected, versionType: git
version: 1da177e4c3f4, lessThan: 241f23032433, status: affected, versionType: git
version: 1da177e4c3f4, lessThan: 528f0ba9f7a4, status: affected, versionType: git
version: 1da177e4c3f4, lessThan: fb9895ab9533, status: affected, versionType: git
version: 1da177e4c3f4, lessThan: 136f69a04e71, status: affected, versionType: git
version: 1da177e4c3f4, lessThan: f74a7afc224a, status: affected, versionType: git
}
{
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 4.14.328, lessThanOrEqual: 4.14.*, status: unaffected, versionType: custom
version: 4.19.297, lessThanOrEqual: 4.19.*, status: unaffected, versionType: custom
version: 5.4.259, lessThanOrEqual: 5.4.*, status: unaffected, versionType: custom
version: 5.10.199, lessThanOrEqual: 5.10.*, status: unaffected, versionType: custom
version: 5.15.136, lessThanOrEqual: 5.15.*, status: unaffected, versionType: custom
version: 6.1.59, lessThanOrEqual: 6.1.*, status: unaffected, versionType: custom
version: 6.5.8, lessThanOrEqual: 6.5.*, status: unaffected, versionType: custom
version: 6.6, lessThanOrEqual: *, status: unaffected, versionType: original_commit_for_fix
}
