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由 Eric Dumazet 提交于
Same reasons than the ones explained in commit 4179cb5a ("vxlan: test dev->flags & IFF_UP before calling netif_rx()") netif_rx_ni() or napi_gro_frags() must be called under a strict contract. At device dismantle phase, core networking clears IFF_UP and flush_all_backlogs() is called after rcu grace period to make sure no incoming packet might be in a cpu backlog and still referencing the device. A similar protocol is used for gro layer. Most drivers call netif_rx() from their interrupt handler, and since the interrupts are disabled at device dismantle, netif_rx() does not have to check dev->flags & IFF_UP Virtual drivers do not have this guarantee, and must therefore make the check themselves. Fixes: 1bd4978a ("tun: honor IFF_UP in tun_get_user()") Signed-off-by: NEric Dumazet <edumazet@google.com> Reported-by: Nsyzbot <syzkaller@googlegroups.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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