selinux: check return value of sel_make_avc_files

stable inclusion
from stable-v5.10.110
commit 962d1f59d5f7e777a47d1691251242d2ab46ef5e
bugzilla: https://gitee.com/openeuler/kernel/issues/I574AL

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=962d1f59d5f7e777a47d1691251242d2ab46ef5e

--------------------------------

[ Upstream commit bcb62828 ]

sel_make_avc_files() might fail and return a negative errno value on
memory allocation failures. Re-add the check of the return value,
dropped in 66f8e2f0 ("selinux: sidtab reverse lookup hash table").

Reported by clang-analyzer:

    security/selinux/selinuxfs.c:2129:2: warning: Value stored to
      'ret' is never read [deadcode.DeadStores]
            ret = sel_make_avc_files(dentry);
            ^     ~~~~~~~~~~~~~~~~~~~~~~~~~~

Fixes: 66f8e2f0 ("selinux: sidtab reverse lookup hash table")
Signed-off-by: NChristian Göttsche <cgzones@googlemail.com>
Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>
[PM: description line wrapping, added proper commit ref]
Signed-off-by: NPaul Moore <paul@paul-moore.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYu Liao <liaoyu15@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

security/selinux/selinuxfs.c

@@ -2124,6 +2124,8 @@ static int sel_fill_super(struct super_block *sb, struct fs_context *fc)
 	}
 
 	ret = sel_make_avc_files(dentry);
+	if (ret)
+		goto err;
 
 	dentry = sel_make_dir(sb->s_root, "ss", &fsi->last_ino);
 	if (IS_ERR(dentry)) {