CVE-2021-47269

In the Linux kernel, the following vulnerability has been resolved: usb:
dwc3: ep0: fix NULL pointer exception There is no validation of the index
from dwc3_wIndex_to_dep() and we might be referring a non-existing ep and
trigger a NULL pointer exception. In certain configurations we might use
fewer eps and the index might wrongly indicate a larger ep index than
existing. By adding this validation from the patch we can actually report a
wrong index back to the caller. In our usecase we are using a composite
device on an older kernel, but upstream might use this fix also.
Unfortunately, I cannot describe the hardware for others to reproduce the
issue as it is a proprietary implementation. [ 82.958261] Unable to handle
kernel NULL pointer dereference at virtual address 00000000000000a4 [
82.966891] Mem abort info: [ 82.969663] ESR = 0x96000006 [ 82.972703]
Exception class = DABT (current EL), IL = 32 bits [ 82.978603] SET = 0, FnV
= 0 [ 82.981642] EA = 0, S1PTW = 0 [ 82.984765] Data abort info: [
82.987631] ISV = 0, ISS = 0x00000006 [ 82.991449] CM = 0, WnR = 0 [
82.994409] user pgtable: 4k pages, 39-bit VAs, pgdp = 00000000c6210ccc [
83.000999] [00000000000000a4] pgd=0000000053aa5003, pud=0000000053aa5003,
pmd=0000000000000000 [ 83.009685] Internal error: Oops: 96000006 [#1]
PREEMPT SMP [ 83.026433] Process irq/62-dwc3 (pid: 303, stack limit =
0x000000003985154c) [ 83.033470] CPU: 0 PID: 303 Comm: irq/62-dwc3 Not
tainted 4.19.124 #1 [ 83.044836] pstate: 60000085 (nZCv daIf -PAN -UAO) [
83.049628] pc : dwc3_ep0_handle_feature+0x414/0x43c [ 83.054558] lr :
dwc3_ep0_interrupt+0x3b4/0xc94 … [ 83.141788] Call trace: [ 83.144227]
dwc3_ep0_handle_feature+0x414/0x43c [ 83.148823]
dwc3_ep0_interrupt+0x3b4/0xc94 [ 83.181546] —[ end trace aac6b5267d84c32f
]—