2019-01-04 05:41:35

by Peng Hao

Subject: [PATCH] security/apparmor/domain: use PTR_ERR_OR_ZERO

The variable 'new' may be NULL, so use PTR_ERR_OR_ZERO instead
of PTR_ERR.

Signed-off-by: Peng Hao <[email protected]>
---
security/apparmor/domain.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index 08c88de..7663589 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -1444,7 +1444,7 @@ int aa_change_profile(const char *fqname, int flags)
new = aa_label_merge(label, target, GFP_KERNEL);
if (IS_ERR_OR_NULL(new)) {
info = "failed to build target label";
- error = PTR_ERR(new);
+ error = PTR_ERR_OR_ZERO(new);
new = NULL;
perms.allow = 0;
goto audit;
--
1.8.3.1

2019-01-17 00:45:28

by John Johansen

Subject: Re: [PATCH] security/apparmor/domain: use PTR_ERR_OR_ZERO

On 1/4/19 1:17 AM, Peng Hao wrote:
> The variable 'new' may be NULL, so use PTR_ERR_OR_ZERO instead
> of PTR_ERR.
>
> Signed-off-by: Peng Hao <[email protected]>

yep that is a problem unfortunately the fix isn't quite right
we don't want to return 0 for an error here. Instead we can
do

diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index 08c88de0ffda..11975ec8d566 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -1444,7 +1444,10 @@ int aa_change_profile(const char *fqname, int flags)
new = aa_label_merge(label, target, GFP_KERNEL);
if (IS_ERR_OR_NULL(new)) {
info = "failed to build target label";
- error = PTR_ERR(new);
+ if (!new)
+ error = -ENOMEM;
+ else
+ error = PTR_ERR(new);
new = NULL;
perms.allow = 0;
goto audit;


I have pulled your patch into my apparmor tree with the above revision


> ---
> security/apparmor/domain.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
> index 08c88de..7663589 100644
> --- a/security/apparmor/domain.c
> +++ b/security/apparmor/domain.c
> @@ -1444,7 +1444,7 @@ int aa_change_profile(const char *fqname, int flags)
> new = aa_label_merge(label, target, GFP_KERNEL);
> if (IS_ERR_OR_NULL(new)) {
> info = "failed to build target label";
> - error = PTR_ERR(new);
> + error = PTR_ERR_OR_ZERO(new);
> new = NULL;
> perms.allow = 0;
> goto audit;
>