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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Kuniyuki Iwashima , netdev@vger.kernel.org, syzkaller , Yi Lai Subject: Re: [PATCH v1 net] ipmr: Call ipmr_fib_lookup() under RCU. 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[0] > > When CONFIG_IP_MROUTE_MULTIPLE_TABLES=n, ipmr_fib_lookup() > uses rcu_dereference() without explicit rcu_read_lock(). > > Although rcu_read_lock_bh() is already held by the caller > __dev_queue_xmit(), lockdep requires explicit rcu_read_lock() > for rcu_dereference(). > > Let's move up rcu_read_lock() in reg_vif_xmit() to > cover ipmr_fib_lookup(). [...] > Fixes: b3b6babf4751 ("ipmr: Free mr_table after RCU grace period.") > Reported-by: syzkaller > Reported-by: Yi Lai > Closes: https://lore.kernel.org/netdev/afrY34dLXNUboevf@ly-workstation/ > Signed-off-by: Kuniyuki Iwashima Reviewed-by: Ido Schimmel