net: rds: acquire refcount on TCP sockets
syzbot is reporting use-after-free read in tcp_retransmit_timer() [1], for TCP socket used by RDS is accessing sock_net() without acquiring a refcount on net namespace. Since TCP's retransmission can happen after a process which created net namespace terminated, we need to explicitly acquire a refcount. Link: https://syzkaller.appspot.com/bug?extid=694120e1002c117747ed [1] Reported-by:syzbot <syzbot+694120e1002c117747ed@syzkaller.appspotmail.com> Fixes: 26abe143 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.") Fixes: 8a681736 ("net: sk_clone_lock() should only do get_net() if the parent is not a kernel socket") Signed-off-by:
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Tested-by:
syzbot <syzbot+694120e1002c117747ed@syzkaller.appspotmail.com> Link: https://lore.kernel.org/r/a5fb1fc4-2284-3359-f6a0-e4e390239d7b@I-love.SAKURA.ne.jp Signed-off-by:
Paolo Abeni <pabeni@redhat.com>
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