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#!/usr/bin/env python3
"""Does any TA write OUTSIDE the shared buffer length declared at LOAD_TA?
LOAD_TA declares cmd_buf_len. If a TA writes past it, the PSP is corrupting host memory
beyond a bound the host set -- a memory-corruption primitive, in the direction that matters
(privileged writer, host victim).
Method: allocate 0x8000, declare cmd_buf_len = 0x1000, fill the WHOLE 0x8000 with a guard
pattern, invoke each command, then check whether any byte at or beyond 0x1000 changed.
Control: bytes below 0x1000 are expected to change (that is the legitimate window); if nothing
changes anywhere, the harness did not exercise the TA and the result is void.
"""
import glob, struct, sys
from tinygrad import Device
import tinygrad.runtime.autogen.am.am as am
adev = Device["AMD"].iface.dev_impl; psp = adev.psp
PAT = 0xA5A5A5A5
DECL = int(__import__('os').environ.get('DECL','0x1000'),0)
TOTAL = 0x8000
def alloc(n):
pa = adev.mm.palloc(n, align=0x1000, zero=True, boot=False); return pa, adev.paddr2mc(pa)
def load(blob):
ap_, amc = alloc(0x80000); cp, cmc = alloc(TOTAL)
n=(len(blob)+3)&~3
adev.vram.view(ap_,n)[:] = blob + b'\x00'*(n-len(blob)); adev.gmc.flush_hdp()
c=am.struct_psp_gfx_cmd_resp(cmd_id=am.GFX_CMD_ID_LOAD_TA); t=c.cmd.cmd_load_ta
t.app_phy_addr_lo,t.app_phy_addr_hi=amc&0xFFFFFFFF,amc>>32; t.app_len=len(blob)
t.cmd_buf_phy_addr_lo,t.cmd_buf_phy_addr_hi=cmc&0xFFFFFFFF,cmc>>32
t.cmd_buf_len=DECL # <-- declare only 0x1000
try:
r=psp._ring_submit(c); return r.resp.status&0xFFFFFFFF, r.resp.session_id, cp
except Exception as e:
try: return int(str(e).strip().split()[-1])&0xFFFFFFFF,None,cp
except Exception: return -1,None,cp
def probe(sid, shm, cid):
buf = bytearray(struct.pack('<I', PAT) * (TOTAL//4))
struct.pack_into('<I', buf, 0, cid)
adev.vram.view(shm, TOTAL)[:] = bytes(buf); adev.gmc.flush_hdp()
c=am.struct_psp_gfx_cmd_resp(cmd_id=am.GFX_CMD_ID_INVOKE_CMD)
iv=c.cmd.cmd_invoke_cmd; iv.session_id, iv.ta_cmd_id = sid, cid
try:
r=psp._ring_submit(c); st=r.resp.status&0xFFFFFFFF
except Exception as e:
try: st=int(str(e).strip().split()[-1])&0xFFFFFFFF
except Exception: st=-1
adev.gmc.flush_hdp()
out=bytes(adev.vram.view(shm, TOTAL)[:])
inside = sum(1 for o in range(4,DECL,4) if struct.unpack_from('<I',out,o)[0]!=PAT)
beyond = [(o,struct.unpack_from('<I',out,o)[0]) for o in range(DECL,TOTAL,4)
if struct.unpack_from('<I',out,o)[0]!=PAT]
return st, inside, beyond
TAS=[('AUC','ta_16-0-0-9_9e9044cf'),('CSU','ta_42-0-0-6_1c874c3c'),('FP','ta_19-0-0-8_7e8be282'),
('GCP','ta_22-0-0-77_7c426e7f'),('MERIT','ta_24-0-0-70_5cd4afda'),('OC','ta_50-0-0-1_cbd47c59'),
('OPM','ta_25-0-0-81_dc596ba6'),('TMZ','ta_29-0-0-4_ce34f538'),('WSPE','ta_30-0-0-38_ec5dee6d'),
('XGMI','ta_32-0-0-20_20a3d1a4')]
only=sys.argv[1].split(',') if len(sys.argv)>1 else None
SKIP={'AUC':{6},'FP':{7}}
for name,stem in TAS:
if only and name not in only: continue
cands=glob.glob('/root/psp/contall/'+stem+'*')
if not cands: continue
st,sid,shm=load(open(cands[0],'rb').read())
if st!=0 or sid is None: print('%-6s LOAD %#x'%(name,st)); continue
tot_in=0; oob=[]
for cid in range(0,12):
if cid in SKIP.get(name,set()): continue
s,ins,bey = probe(sid, shm, cid)
tot_in += ins
if bey: oob.append((cid,s,len(bey),bey[:4]))
verdict = ('OOB WRITES: %s'%oob[:3]) if oob else ('no writes past the declared length'
if tot_in else 'VOID: nothing changed anywhere (harness did not exercise the TA)')
print('%-6s in-window dwords changed=%-5d %s'%(name,tot_in,verdict))
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