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After ipv6_add_addr() publishes it, addrconf_ifdown() can mark the > new ifaddr DEAD, clear its route, and unlink it before the recovery path > takes ifp2->lock. > > The recovery path then unconditionally changes the state back to PREDAD > and queues delayed DAD work. The MTU teardown path can leave IF_READY > set. For an optimistic address, addrconf_dad_begin() can consequently > pass the cleared NULL route to ip6_ins_rt(). > > This follow-on was found by source review and was not separately > triggered at runtime. > > The new ifaddr is already initialized in PREDAD. Under ifp2->lock, record > the retry and queue DAD only if teardown has not changed the state to > DEAD. If teardown wins after this check, the work observes DEAD and exits > without reviving the address. > > This complements the existing lock_errdad check that preserves the original > ifaddr's DEAD state after the same function reacquires its lock. > > Fixes: 5f40ef77adb2 ("ipv6: do retries on stable privacy addresses") > Cc: stable@vger.kernel.org > Reported-by: Sashiko > Closes: https://lore.kernel.org/r/179161099408.434549.14449036924552933828@kernel.org > Link: https://lore.kernel.org/r/20260513025509.3776405-1-lilinmao@kylinos.cn > Assisted-by: LLM > Signed-off-by: Daehyeon Ko <4ncienth@gmail.com> Same comment as on the previous patch. My diff [1] was simpler and your commit message admits that it's fine: "If teardown wins after this check, the work observes DEAD and exits without reviving the address" Reviewed-by: Ido Schimmel [1] https://lore.kernel.org/netdev/20261012151316.GA798355@shredder/