5038517119
find_set_and_id() is called when the NFNL_SUBSYS_IPSET mutex is held. However, in the error path there can be a follow-up recvmsg() without the mutex held. Use the start() function of struct netlink_dump_control instead of dump() to verify and report if the specified set does not exist. Thanks to Pablo Neira Ayuso for helping me to understand the subleties of the netlink protocol. Reported-by: syzbot+fc69d7cb21258ab4ae4d@syzkaller.appspotmail.com Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>