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As a result: > > - clients that did not set NLM_F_ACK block on recv() indefinitely > waiting for a CGROUPSTATS_CMD_NEW message that is never emitted; > - clients that set NLM_F_ACK receive a misleading "success" ACK > (errno == 0) with no statistics payload. > > Return -EBADF instead so the netlink layer propagates the error to > userspace as expected. > > Signed-off-by: Yiyang Chen > --- > kernel/taskstats.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/taskstats.c b/kernel/taskstats.c > index 2cd0172d0516..8d115670a3ca 100644 > --- a/kernel/taskstats.c > +++ b/kernel/taskstats.c > @@ -423,7 +423,7 @@ static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info) > fd = nla_get_u32(info->attrs[CGROUPSTATS_CMD_ATTR_FD]); > CLASS(fd, f)(fd); > if (fd_empty(f)) > - return 0; > + return -EBADF; > > size = nla_total_size(sizeof(struct cgroupstats)); > Thanks! Acked-by: Balbir Singh