[PATCH 5.15 693/917] apparmor: fix error check

Greg Kroah-Hartman
2021-11-16T00:34:17Z

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 e68bcedca976b..6222fdfebe4e5 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
--
2.33.0