On 2019/3/5 23:43, Dan Carpenter wrote: > Hello YueHaibing, > > This is a semi-automatic email about new static checker warnings. > > The patch 6377f787aeb9: "appletalk: Fix use-after-free in > atalk_proc_exit" from Mar 1, 2019, leads to the following Smatch > complaint: > > net/appletalk/ddp.c:1952 atalk_init() > error: we previously assumed 'ddp_dl' could be null (see line 1924) > Yes, all the callers of register_snap_client seems not handling the null, it just print a warning. I'll try fix it. Thanks! > net/appletalk/ddp.c > 1923 ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv); > 1924 if (!ddp_dl) > ^^^^^^^ > Check > > 1925 printk(atalk_err_snap); > 1926 > 1927 dev_add_pack(<alk_packet_type); > 1928 dev_add_pack(&ppptalk_packet_type); > 1929 > 1930 rc = register_netdevice_notifier(&ddp_notifier); > 1931 if (rc) > 1932 goto out_sock; > 1933 > 1934 aarp_proto_init(); > 1935 rc = atalk_proc_init(); > 1936 if (rc) > 1937 goto out_aarp; > 1938 > 1939 rc = atalk_register_sysctl(); > 1940 if (rc) > 1941 goto out_proc; > 1942 out: > 1943 return rc; > 1944 out_proc: > 1945 atalk_proc_exit(); > 1946 out_aarp: > 1947 aarp_cleanup_module(); > 1948 unregister_netdevice_notifier(&ddp_notifier); > 1949 out_sock: > 1950 dev_remove_pack(&ppptalk_packet_type); > 1951 dev_remove_pack(<alk_packet_type); > 1952 unregister_snap_client(ddp_dl); > ^^^^^^ > Unchecked dereference. > > 1953 sock_unregister(PF_APPLETALK); > 1954 out_proto: > > regards, > dan carpenter > >
