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authorYueHaibing <yuehaibing@huawei.com>2019-03-14 13:47:59 +0800
committerDavid S. Miller <davem@davemloft.net>2019-03-15 11:25:48 -0700
commit9804501fa1228048857910a6bf23e085aade37cc (patch)
treed51cf99870eb02f0b90107a449586d2ab20dbe9e /net/appletalk
parentMerge branch 'akpm' (patches from Andrew) (diff)
downloadlinux-dev-9804501fa1228048857910a6bf23e085aade37cc.tar.xz
linux-dev-9804501fa1228048857910a6bf23e085aade37cc.zip
appletalk: Fix potential NULL pointer dereference in unregister_snap_client
register_snap_client may return NULL, all the callers check it, but only print a warning. This will result in NULL pointer dereference in unregister_snap_client and other places. It has always been used like this since v2.6 Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/appletalk')
-rw-r--r--net/appletalk/aarp.c15
-rw-r--r--net/appletalk/ddp.c20
2 files changed, 24 insertions, 11 deletions
diff --git a/net/appletalk/aarp.c b/net/appletalk/aarp.c
index 49a16cee2aae..420a98bf79b5 100644
--- a/net/appletalk/aarp.c
+++ b/net/appletalk/aarp.c
@@ -879,15 +879,24 @@ static struct notifier_block aarp_notifier = {
static unsigned char aarp_snap_id[] = { 0x00, 0x00, 0x00, 0x80, 0xF3 };
-void __init aarp_proto_init(void)
+int __init aarp_proto_init(void)
{
+ int rc;
+
aarp_dl = register_snap_client(aarp_snap_id, aarp_rcv);
- if (!aarp_dl)
+ if (!aarp_dl) {
printk(KERN_CRIT "Unable to register AARP with SNAP.\n");
+ return -ENOMEM;
+ }
timer_setup(&aarp_timer, aarp_expire_timeout, 0);
aarp_timer.expires = jiffies + sysctl_aarp_expiry_time;
add_timer(&aarp_timer);
- register_netdevice_notifier(&aarp_notifier);
+ rc = register_netdevice_notifier(&aarp_notifier);
+ if (rc) {
+ del_timer_sync(&aarp_timer);
+ unregister_snap_client(aarp_dl);
+ }
+ return rc;
}
/* Remove the AARP entries associated with a device. */
diff --git a/net/appletalk/ddp.c b/net/appletalk/ddp.c
index 795fbc6c06aa..709d2542f729 100644
--- a/net/appletalk/ddp.c
+++ b/net/appletalk/ddp.c
@@ -1904,9 +1904,6 @@ static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
EXPORT_SYMBOL(atrtr_get_dev);
EXPORT_SYMBOL(atalk_find_dev_addr);
-static const char atalk_err_snap[] __initconst =
- KERN_CRIT "Unable to register DDP with SNAP.\n";
-
/* Called by proto.c on kernel start up */
static int __init atalk_init(void)
{
@@ -1921,17 +1918,22 @@ static int __init atalk_init(void)
goto out_proto;
ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
- if (!ddp_dl)
- printk(atalk_err_snap);
+ if (!ddp_dl) {
+ pr_crit("Unable to register DDP with SNAP.\n");
+ goto out_sock;
+ }
dev_add_pack(&ltalk_packet_type);
dev_add_pack(&ppptalk_packet_type);
rc = register_netdevice_notifier(&ddp_notifier);
if (rc)
- goto out_sock;
+ goto out_snap;
+
+ rc = aarp_proto_init();
+ if (rc)
+ goto out_dev;
- aarp_proto_init();
rc = atalk_proc_init();
if (rc)
goto out_aarp;
@@ -1945,11 +1947,13 @@ out_proc:
atalk_proc_exit();
out_aarp:
aarp_cleanup_module();
+out_dev:
unregister_netdevice_notifier(&ddp_notifier);
-out_sock:
+out_snap:
dev_remove_pack(&ppptalk_packet_type);
dev_remove_pack(&ltalk_packet_type);
unregister_snap_client(ddp_dl);
+out_sock:
sock_unregister(PF_APPLETALK);
out_proto:
proto_unregister(&ddp_proto);