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From:   trix@redhat.com
To:     john.johansen@canonical.com, jmorris@namei.org, serge@hallyn.com,
        natechancellor@gmail.com, ndesaulniers@google.com
Cc:     linux-security-module@vger.kernel.org,
        linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com,
        Tom Rix <trix@redhat.com>
Subject: [PATCH] apparmor: fix error check
Date:   Sun,  4 Oct 2020 07:24:22 -0700
Message-Id: <20201004142422.5717-1-trix@redhat.com>
Precedence: bulk

From: Tom Rix <trix@redhat.com>

clang static analysis reports this representative problem:

label.c:1463:16: warning: Assigned value is garbage or undefined
        label->hname = name;
                     ^ ~~~~

In aa_update_label_name(), this the problem block of code

	if (aa_label_acntsxprint(&name, ...) == -1)
		return res;

On failure, aa_label_acntsxprint() has a more complicated return
that just -1.  So check for a negative return.

It was also noted that the aa_label_acntsxprint() main comment refers
to a nonexistent parameter, so clean up the comment.

Fixes: f1bd904175e8 ("apparmor: add the base fns() for domain labels")
Signed-off-by: Tom Rix <trix@redhat.com>
---
 security/apparmor/label.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/security/apparmor/label.c b/security/apparmor/label.c
index e68bcedca976..6222fdfebe4e 100644
--- a/security/apparmor/label.c
+++ b/security/apparmor/label.c
@@ -1454,7 +1454,7 @@ bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp)
 	if (label->hname || labels_ns(label) != ns)
 		return res;
 
-	if (aa_label_acntsxprint(&name, ns, label, FLAGS_NONE, gfp) == -1)
+	if (aa_label_acntsxprint(&name, ns, label, FLAGS_NONE, gfp) < 0)
 		return res;
 
 	ls = labels_set(label);
@@ -1704,7 +1704,7 @@ int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label,
 
 /**
  * aa_label_acntsxprint - allocate a __counted string buffer and print label
- * @strp: buffer to write to. (MAY BE NULL if @size == 0)
+ * @strp: buffer to write to.
  * @ns: namespace profile is being viewed from
  * @label: label to view (NOT NULL)
  * @flags: flags controlling what label info is printed
-- 
2.18.1