Zhang Yan
2016-Mar-11 12:22 UTC
[Bridge] PROBLEM：there exists a wrong return value of function br_sysfs_addbr()
Bug Description:
In function br_sysfs_addbr() at net/bridge/br_sysfs_br.c:line 851, return
value "0" indicates success.
if function kobject_create_and_add() at line 871 fails, function
br_sysfs_addbr() will return the value of variable "err", which is 0
because sysfs_create_bin_file() at line 864 succeeded previously.But, function
br_sysfs_addbr() should propagate the error and return a negative number to its
caller functions.
The related code snippets in br_sysfs_addbr are as following.
br_sysfs_addbr @@ net/bridge/br_sysfs_br.c:line 851
851 int br_sysfs_addbr(struct net_device *dev)
852 {
...
864 err = sysfs_create_bin_file(brobj, &bridge_forward);
865 if (err) {
866 pr_info("%s: can't create attribute file %s/%s\n",
867 __func__, dev->name, bridge_forward.attr.name);
868 goto out2;
869 }
870
871 br->ifobj = kobject_create_and_add(SYSFS_BRIDGE_PORT_SUBDIR, brobj);
872 if (!br->ifobj) {
873 pr_info("%s: can't add kobject (directory) %s/%s\n",
874 __func__, dev->name, SYSFS_BRIDGE_PORT_SUBDIR);
875 goto out3;
876 }
877 return 0;
878 out3:
879 sysfs_remove_bin_file(&dev->dev.kobj, &bridge_forward);
880 out2:
881 sysfs_remove_group(&dev->dev.kobj, &bridge_group);
882 out1:
883 return err;
884
885 }
Generally, when the call to kobject_create_and_add() fails, the return value of
caller functions
should be different from another return value set when the call to
kobject_create_and_add() succeeds,
like the following codes in another file.
kobject_create_and_add @@ arch/x86/kernel/cpu/mcheck/mce_amd.c:line 711
677 static int threshold_create_bank(unsigned int cpu, unsigned int bank)
678 {
...
711 b->kobj = kobject_create_and_add(name, &dev->kobj);
712 if (!b->kobj) {
713 err = -EINVAL;
714 goto out_free;
715 }
...
}
Kernel version:4.5
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