2023-09-19 01:58:24

by Li kunyu

Subject: [PATCH v2] apparmor/file: Removing unnecessary initial values for variable pointers

These variable pointers are assigned during use and do not need to be
initialized for assignment.

Signed-off-by: Li kunyu <[email protected]>
---
v2: Fix timestamp issues

security/apparmor/file.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/security/apparmor/file.c b/security/apparmor/file.c
index 698b124e649f..12eafdf18fc0 100644
--- a/security/apparmor/file.c
+++ b/security/apparmor/file.c
@@ -264,7 +264,7 @@ int aa_path_perm(const char *op, struct aa_label *label,
{
struct aa_perms perms = {};
struct aa_profile *profile;
- char *buffer = NULL;
+ char *buffer;
int error;

flags |= PATH_DELEGATE_DELETED | (S_ISDIR(cond->mode) ? PATH_IS_DIR :
@@ -412,7 +412,7 @@ int aa_path_link(struct aa_label *label, struct dentry *old_dentry,
d_backing_inode(old_dentry)->i_uid,
d_backing_inode(old_dentry)->i_mode
};
- char *buffer = NULL, *buffer2 = NULL;
+ char *buffer, *buffer2;
struct aa_profile *profile;
int error;

--
2.18.2

2023-09-28 19:59:04

by Serge E. Hallyn

Subject: Re: [PATCH v2] apparmor/file: Removing unnecessary initial values for variable pointers

On Thu, Sep 28, 2023 at 10:36:16AM -0700, John Johansen wrote:
> On 9/18/23 18:56, Li kunyu wrote:
> > These variable pointers are assigned during use and do not need to be
> > initialized for assignment.
> >
> > Signed-off-by: Li kunyu <[email protected]>
> > ---
> > v2: Fix timestamp issues
> >
> > security/apparmor/file.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/security/apparmor/file.c b/security/apparmor/file.c
> > index 698b124e649f..12eafdf18fc0 100644
> > --- a/security/apparmor/file.c
> > +++ b/security/apparmor/file.c
> > @@ -264,7 +264,7 @@ int aa_path_perm(const char *op, struct aa_label *label,
> > {
> > struct aa_perms perms = {};
> > struct aa_profile *profile;
> > - char *buffer = NULL;
> > + char *buffer;
>
> this is okay
>
> > int error;
> > flags |= PATH_DELEGATE_DELETED | (S_ISDIR(cond->mode) ? PATH_IS_DIR :
> > @@ -412,7 +412,7 @@ int aa_path_link(struct aa_label *label, struct dentry *old_dentry,
> > d_backing_inode(old_dentry)->i_uid,
> > d_backing_inode(old_dentry)->i_mode
> > };
> > - char *buffer = NULL, *buffer2 = NULL;
> > + char *buffer, *buffer2;
>
> this can cause an oops if buffer2 allocation fails. There are a couple of ways I can
> see to fix this, do you want to take a crack at it.
>
>
> > struct aa_profile *profile;
> > int error;

I don't whether this kind of thing has become in vogue, but while indeed
the first case is okay right now, it becomes more likely that a future patch
to this function will inadvertently goto aa_put_buffer(buffer) before the
aa_get_buffer call. I would not have NACKed an original version of this fn
without the = NULL, but I'm not in favor of dropping it.

-serge

2023-09-28 20:24:41

by John Johansen

Subject: Re: [PATCH v2] apparmor/file: Removing unnecessary initial values for variable pointers

On 9/18/23 18:56, Li kunyu wrote:
> These variable pointers are assigned during use and do not need to be
> initialized for assignment.
>
> Signed-off-by: Li kunyu <[email protected]>
> ---
> v2: Fix timestamp issues
>
> security/apparmor/file.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/security/apparmor/file.c b/security/apparmor/file.c
> index 698b124e649f..12eafdf18fc0 100644
> --- a/security/apparmor/file.c
> +++ b/security/apparmor/file.c
> @@ -264,7 +264,7 @@ int aa_path_perm(const char *op, struct aa_label *label,
> {
> struct aa_perms perms = {};
> struct aa_profile *profile;
> - char *buffer = NULL;
> + char *buffer;

this is okay

> int error;
>
> flags |= PATH_DELEGATE_DELETED | (S_ISDIR(cond->mode) ? PATH_IS_DIR :
> @@ -412,7 +412,7 @@ int aa_path_link(struct aa_label *label, struct dentry *old_dentry,
> d_backing_inode(old_dentry)->i_uid,
> d_backing_inode(old_dentry)->i_mode
> };
> - char *buffer = NULL, *buffer2 = NULL;
> + char *buffer, *buffer2;

this can cause an oops if buffer2 allocation fails. There are a couple of ways I can
see to fix this, do you want to take a crack at it.


> struct aa_profile *profile;
> int error;
>