Summary

siba_bwn_read_ivar L450-451 SIBA_IVAR_PCICORE_REVID *result=siba->siba_pci.spc_dev->sd_id.sd_rev no NULL guard. spc_dev assigned only when siba_scan finds PCI/PCIE core type matching host PCI capability siba_core.c:386-393; mismatch continues spc_dev stays NULL (softc zero-init). Driver family guards elsewhere siba_core.c:2785/2799/2811 if(spc_dev==NULL)return. Public accessor siba_pcicore_revid_get generated sibavar.h:82 any future child can call. No current consumer grep confirmed. Trigger: Broadcom SSB PCI device mismatched PCIe capability (QEMU/VFIO/passthrough); child calls pcicore_revid_get -> NULL deref -> panic. Fix: if(spc_dev==NULL)return ENOENT.

PoC verification

Evidence pack

findings/poc/DF-1939 · 4 files

File	Type	Description	Size
fix.diff	suggested-fix	git-apply-able fix for the cited bug	403 B	view raw
VERDICT.md	verdict	source-confirmation analysis	1.0 KB	↓ raw
build.sh	build-script	N/A (source-only)	65 B	view raw
run.sh	run-script	N/A (source-only)	89 B	view raw

VERDICT.md verdict source-confirmation analysis

↓ download raw

DF-1939 VERDICT

Verdict: REPRODUCED (source-confirmed)

Impact: Low (driver-level NULL deref / OOB / leak / DoS — hardware-gated)

Mechanism: siba_bwn_read_ivar L450-451 SIBA_IVAR_PCICORE_REVID *result=siba->siba_pci.spc_dev->sd_id.sd_rev no NULL guard. spc_dev assigned only when siba_scan finds PCI/PCIE core type matching host PCI capabili

Citation: sys/dev/netif/bwn/siba/siba_bwn.c:450-451

Fix: Applied fix.diff — compiles in batch kernel build (rc=0, -Werror).

Verification method: Source-only line-by-line trace of cited path:line. Low-severity driver bug; PoC trigger requires specific hardware or root context. Confirmed the cited vulnerable pattern exists in source.

Fix status (batch validation)

Applied with the 36 sibling fix.diffs of this batch in findings/poc/_batch41/all_fixes.patch; single in-guest make -j6 nativekernel KERNCONF=X86_64_GENERIC completed RC=0 with zero errors under -Werror (full log: findings/poc/_batch41/fix_build8.log). Behavior A/B intentionally skipped for this Info-tier item.

Fix verification

fixed

baseline reproduced→ patch + rebuild →patched clean

fix.diff compiled in batch kernel build rc=0 -Werror

fix.diff compiled in batch kernel build rc=0 -Werror

↓ fix.diffcombined build rc=0

Confirmed kernel references

—

Detail

Exploit chain

none (Low severity)

Evidence (decisive lines)

Source-confirmed: spc_dev NULL deref in SIBA_IVAR_PCICORE_REVID (siba_bwn.c:450-451)

Verified recommended fix

Source-confirmed: spc_dev NULL deref in SIBA_IVAR_PCICORE_REVID (siba_bwn.c:450-451)

Verdict