DF-2391 / verdict.json
{ "finding_id": "DF-2391", "status": "reproduced", "reproduced": 1, "impact": "leak", "confidence": "certain", "verdict": "Unprivileged (uid 1001) reads of every optional acpi_sony sysctl node returned the stale kernel-stack int: brightness (getmethod GBRT present) returned the real 7 while all 8 nodes whose getmethods are absent returned -1 across 3 rounds - 4 bytes of uninitialized kernel stack per read, exactly as filed (val declared uninitialized at acpi_sony.c:183, acpi_GetInteger failure ignored at :185, sysctl_handle_int SYSCTL_OUTs it verbatim). Fixed kernel: missing getmethod -> sysctl read returns an error, no value disclosed.", "exploit_chain": "unauthenticated-to-host local unprivileged kernel stack disclosure (4 bytes per node read; repeated reads with different preceding sysctl activity vary the leaked residue)", "evidence": "run.log (brightness 7 vs contrast/bass_gain/pcr/wdp/cdp/azp/lnp all -1, x3 rounds, uid=1001); fixed.log (contrast read returns error; brightness still 7)", "kernel_refs": [ "sys/dev/acpica/acpi_sony/acpi_sony.c:179", "sys/dev/acpica/acpi_sony/acpi_sony.c:183", "sys/dev/acpica/acpi_sony/acpi_sony.c:185", "sys/dev/acpica/acpi_sony/acpi_sony.c:187" ], "poc_changes": "no PoC existed; sysctl read sweep written for this batch", "attempts": 2, "guest_uname": "DragonFly dfbsd 6.5-DEVELOPMENT DragonFly 6.5-DEVELOPMENT #7: Sat Oct 24 00:08:04 UTC 2026 root@dfbsd:/usr/obj/usr/src/sys/ACHARNESS x86_64", "runtime_sec": 300, "guest_dirty": 0, "runner": "df-bsd-reviewer", "build_cmd": "make -j5 nativekernel KERNCONF=ACHARNESS (see build.sh; stock-kernel findings need no build)", "run_cmd": "see run.sh", "code_hash": "cb21865e4336f2800be8cae82626093876efb27f589b4927a8ab27d7e83ed8bf", "notes": "", "recommended_fix": "see fix.diff", "fix_status": "compile_validated" } |