[PATCH] apparmor: fix aa_label_asxprint return check

[PATCH] apparmor: fix aa_label_asxprint return check

[trix]

From: Tom Rix <trix@redhat.com>

Clang static analysis reports this issue
label.c:1802:3: warning: 2nd function call argument
  is an uninitialized value
  pr_info("%s", str);
  ^~~~~~~~~~~~~~~~~~

str is set from a successful call to aa_label_asxprint(&str, ...)
On failure a negative value is returned, not a -1.  So change
the check.

Fixes: f1bd904175e8 ("apparmor: add the base fns() for domain labels")
Signed-off-by: Tom Rix <trix@redhat.com>
---
 security/apparmor/label.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/security/apparmor/label.c b/security/apparmor/label.c
index 9eb9a9237926..a658b67c784c 100644
--- a/security/apparmor/label.c
+++ b/security/apparmor/label.c
@@ -1744,7 +1744,7 @@ void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns,
 	if (!use_label_hname(ns, label, flags) ||
 	    display_mode(ns, label, flags)) {
 		len  = aa_label_asxprint(&name, ns, label, flags, gfp);
-		if (len == -1) {
+		if (len < 0) {
 			AA_DEBUG("label print error");
 			return;
 		}
@@ -1772,7 +1772,7 @@ void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns,
 		int len;
 
 		len = aa_label_asxprint(&str, ns, label, flags, gfp);
-		if (len == -1) {
+		if (len < 0) {
 			AA_DEBUG("label print error");
 			return;
 		}
@@ -1795,7 +1795,7 @@ void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags,
 		int len;
 
 		len = aa_label_asxprint(&str, ns, label, flags, gfp);
-		if (len == -1) {
+		if (len < 0) {
 			AA_DEBUG("label print error");
 			return;
 		}
-- 
2.26.3

Re: [PATCH] apparmor: fix aa_label_asxprint return check

[John Johansen]

On 2/13/22 13:32, trix@redhat.com wrote:
> From: Tom Rix <trix@redhat.com>
> 
> Clang static analysis reports this issue
> label.c:1802:3: warning: 2nd function call argument
>   is an uninitialized value
>   pr_info("%s", str);
>   ^~~~~~~~~~~~~~~~~~
> 
> str is set from a successful call to aa_label_asxprint(&str, ...)
> On failure a negative value is returned, not a -1.  So change
> the check.
> 
> Fixes: f1bd904175e8 ("apparmor: add the base fns() for domain labels")
> Signed-off-by: Tom Rix <trix@redhat.com>

Acked-by: John Johansen <john.johansen@canonical.com>

thanks I have pulled this into my tree

> ---
>  security/apparmor/label.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/security/apparmor/label.c b/security/apparmor/label.c
> index 9eb9a9237926..a658b67c784c 100644
> --- a/security/apparmor/label.c
> +++ b/security/apparmor/label.c
> @@ -1744,7 +1744,7 @@ void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns,
>  	if (!use_label_hname(ns, label, flags) ||
>  	    display_mode(ns, label, flags)) {
>  		len  = aa_label_asxprint(&name, ns, label, flags, gfp);
> -		if (len == -1) {
> +		if (len < 0) {
>  			AA_DEBUG("label print error");
>  			return;
>  		}
> @@ -1772,7 +1772,7 @@ void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns,
>  		int len;
>  
>  		len = aa_label_asxprint(&str, ns, label, flags, gfp);
> -		if (len == -1) {
> +		if (len < 0) {
>  			AA_DEBUG("label print error");
>  			return;
>  		}
> @@ -1795,7 +1795,7 @@ void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags,
>  		int len;
>  
>  		len = aa_label_asxprint(&str, ns, label, flags, gfp);
> -		if (len == -1) {
> +		if (len < 0) {
>  			AA_DEBUG("label print error");
>  			return;
>  		}