Missing resource cleanup when bus_dma_tag_create fails in fwohci_pci_attach
Summary
fwohci_pci_attach at fwohci_pci.c:320-324: when bus_dma_tag_create fails, returns ENOMEM without calling fwohci_pci_detach(self). By this point three resources allocated: sc->bsr (bus_alloc_resource :267), sc->irq_res (bus_alloc_resource :278), interrupt handler (bus_setup_intr :287). None freed before return. Other error paths at :282/:296/:330 correctly call fwohci_pci_detach(self). device_doattach (subr_bus.c:2108-2124) does NOT call device_detach when DEVICE_ATTACH returns non-zero so leaked resources never reclaimed. Requires bus_dma_tag_create failure under kernel memory pressure. Impact: permanent resource leak (MMIO mapping, IRQ line, interrupt handler slot) per occurrence.
Discussion (0)
PoC verification
Evidence pack
findings/poc/DF-1098 Β· 3 files| File | Type | Description | Size | |
|---|---|---|---|---|
| VERDICT.md | verdict | Source-confirmation verdict for DF-1098 | 621 B | β raw |
| fix.diff | suggested-fix | Call fwohci_pci_detach on bus_dma_tag_create failure | 464 B | view raw |
| ../fix_build.log | build-log | Batch kernel build log (all fixes, rc=0) | 5.6 MB | β download |
DF-1098 Verification Verdict
Severity: Low Impact class: leak Verification method: Source-only confirmation (HW-gated, not triggerable on QEMU guest)
Verdict: REPRODUCED (source-confirmed)
The bug is confirmed in the audited source at the cited path:line. Triggerable but requires specific driver/config.
Fix: Call fwohci_pci_detach on bus_dma_tag_create failure
Fix applied and validated in batch kernel build (rc=0, -Werror).
Fix validation
All 41-fix patches batched into single make -j6 nativekernel KERNCONF=X86_64_GENERIC build.
Build result: rc=0, 0 errors (full -Werror clean).
Fix verification
fixedVALIDATED: fix.diff applies cleanly + batch kernel build rc=0 -Werror; bug HW/module/runtime-gated, no runtime PoC re-test possible on guest.
VALIDATED: fix.diff applies cleanly + batch kernel build rc=0 -Werror; bug HW/module/runtime-gated, no runtime PoC re-test possible on guest.
Confirmed kernel references
β
Detail
Exploit chain
none
Evidence (decisive lines)
REPRODUCED (source-only): fwohci_pci_attach returns ENOMEM on bus_dma_tag_create failure without calling fwohci_pci_detach, leaking sc->bsr and sc->irq_res.
Verified recommended fix
REPRODUCED (source-only): fwohci_pci_attach returns ENOMEM on bus_dma_tag_create failure without calling fwohci_pci_detach, leaking sc->bsr and sc->irq_res.
Verdict
REPRODUCED (source-only): fwohci_pci_attach returns ENOMEM on bus_dma_tag_create failure without calling fwohci_pci_detach, leaking sc->bsr and sc->irq_res.
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