From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Tom Rix <trix@redhat.com>,
        Nick Desaulniers <ndesaulniers@google.com>,
        John Johansen <john.johansen@canonical.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 289/355] apparmor: fix error check
Date:   Mon, 15 Nov 2021 18:03:33 +0100
Message-Id: <20211115165323.074054510@linuxfoundation.org>
In-Reply-To: <20211115165313.549179499@linuxfoundation.org>
References: <20211115165313.549179499@linuxfoundation.org>
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From: Tom Rix <trix@redhat.com>

[ Upstream commit d108370c644b153382632b3e5511ade575c91c86 ]

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>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 5f324d63ceaa3..747a734a08246 100644
--- a/security/apparmor/label.c
+++ b/security/apparmor/label.c
@@ -1459,7 +1459,7 @@ 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);
@@ -1709,7 +1709,7 @@ 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
-- 
2.33.0