tipc: fix uninit skb->data in tipc_nl_compat_dumpit()
__tipc_nl_compat_dumpit() has two callers, and it expects them to pass a valid nlmsghdr via arg->data. This header is artificial and crafted just for __tipc_nl_compat_dumpit(). tipc_nl_compat_publ_dump() does so by putting a genlmsghdr as well as some nested attribute, TIPC_NLA_SOCK. But the other caller tipc_nl_compat_dumpit() does not, this leaves arg->data uninitialized on this call path. Fix this by just adding a similar nlmsghdr without any payload in tipc_nl_compat_dumpit(). This bug exists since day 1, but the recent commit 6ea67769 ("net: tipc: prepare attrs in __tipc_nl_compat_dumpit()") makes it easier to appear. Reported-and-tested-by:<syzbot+0e7181deafa7e0b79923@syzkaller.appspotmail.com> Fixes: d0796d1e ("tipc: convert legacy nl bearer dump to nl compat") Cc: Jon Maloy <jmaloy@redhat.com> Cc: Ying Xue <ying.xue@windriver.com> Cc: Richard Alpe <richard.alpe@ericsson.com> Signed-off-by:
Cong Wang <xiyou.wangcong@gmail.com> Acked-by:
Ying Xue <ying.xue@windriver.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
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8c26544f