Replace 1-element array in fs/dlm/dlm_internal.h

[GustavoARSilva]

Replace one-element array with flexible-array member in fs/dlm/dlm_internal.h

551 /*
552  * The max number of resources per rsbtbl bucket that shrink will attempt
553  * to remove in each iteration.
554  */
555 
556 #define DLM_REMOVE_NAMES_MAX 8
557 
558 struct dlm_ls {
559         struct list_head        ls_list;        /* list of lockspaces */
...
669         const struct dlm_lockspace_ops *ls_ops;
670         void                    *ls_ops_arg;
671 
672         int                     ls_namelen;
673         char                    ls_name[1];
674 };

Audit (at least) all these places where the flex array is being used:

diff -u -p ./fs/dlm/lockspace.c /tmp/nothing/fs/dlm/lockspace.c
--- ./fs/dlm/lockspace.c
+++ /tmp/nothing/fs/dlm/lockspace.c
@@ -220,7 +220,6 @@ static int dlm_uevent(struct kobject *ko
 {
        struct dlm_ls *ls = container_of(kobj, struct dlm_ls, ls_kobj);

-       add_uevent_var(env, "LOCKSPACE=%s", ls->ls_name);
        return 0;
 }

@@ -455,7 +454,6 @@ static int new_lockspace(const char *nam
                WARN_ON(ls->ls_create_count <= 0);
                if (ls->ls_namelen != namelen)
                        continue;
-               if (memcmp(ls->ls_name, name, namelen))
                        continue;
                if (flags & DLM_LSFL_NEWEXCL) {
                        error = -EEXIST;
@@ -476,7 +474,6 @@ static int new_lockspace(const char *nam
        ls = kzalloc(sizeof(struct dlm_ls) + namelen, GFP_NOFS);
        if (!ls)
                goto out;
-       memcpy(ls->ls_name, name, namelen);
        ls->ls_namelen = namelen;
        ls->ls_lvblen = lvblen;
        atomic_set(&ls->ls_count, 0);
@@ -646,7 +643,6 @@ static int new_lockspace(const char *nam

        ls->ls_kobj.kset = dlm_kset;
        error = kobject_init_and_add(&ls->ls_kobj, &dlm_ktype, NULL,
-                                    "%s", ls->ls_name);
        if (error)
                goto out_recoverd;
        kobject_uevent(&ls->ls_kobj, KOBJ_ADD);

[PauloMigAlmeida]

Hi @GustavoARSilva , I've been meaning to start contributing to the KSPP project. Could you assign this task to me? (or even you think that there is a more suitable first issue, feel free to assign that one to me).

I just want to make sure I'm not gonna be working on something that you are currently looking at.

I will drop an 'self-introduction' to the mailing list later today to share my skills and time commitment that I'm willing to dedicate to this project.

Thanks!

[GustavoARSilva]

Hi @GustavoARSilva , I've been meaning to start contributing to the KSPP project. Could you assign this task to me? (or even you think that there is a more suitable first issue, feel free to assign that one to me).

Awesome. Go for it. :)

We have a "good first issue" tag for those we consider are more trivial issues to address. You can check them out and decide if you want to start there.

Thanks

Gustavo

[PauloMigAlmeida]

Patch for this: https://lore.kernel.org/linux-hardening/Y0ICbf8tCtXMn+W0@mail.google.com/T/#u

[PauloMigAlmeida]

I got betrayed by a fat finger mistake (which messed up the body of my previous patch) 🤦🏻 .

Patch v2 for this: https://lore.kernel.org/linux-hardening/Y0IFEUjwXGZFf7bB@mail.google.com/T/#u

[PauloMigAlmeida]

Patch has been accepted