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DF-5256

DragonFly-only unlocked traversal of ifp->if_multiaddrs in urtwn_set_multi (upstream takes if_maddr_rlock)

Summary

The #ifdef __DragonFly__ branches walk the multicast TAILQ with no maddr lock while concurrent if_addmulti/if_delmulti (unpriv socket group joins, IGMP timers) mutate it - freed ifma use or torn link pointers -> panic in init/SIOCADDMULTI. DF branch dropped the upstream if_maddr_rlock; tokenization may partially mask (hence speculative). Port-the-lock fix.

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PoC verification

Evidence pack

findings/poc/DF-5256 Β· 1 files
FileTypeDescriptionSize
verdict.json file 994 B view raw

Fix verification

not_testable
baseline no→ patch + rebuild →patched clean
per-fix-DF-5256

Confirmed kernel references

Detail

Evidence (decisive lines)

static trace in finding markdown

Verified recommended fix

see finding markdown

Verdict

untested (hardware-gated; static trace, deterministic leak logic / narrow race window)