| Message ID | 20220128202858.96935-4-vbendel@redhat.com (mailing list archive) |
|---|---|
| State | Rejected |
| Delegated to: | Paul Moore |
| Headers | show |
| Series | selinux: Fix and clean policydb->cond_list error paths | expand |
On Fri, Jan 28, 2022 at 3:29 PM <vbendel@redhat.com> wrote: > From: Vratislav Bendel <vbendel@redhat.com> > > On error path from cond_read_list() and duplicate_policydb_cond_list() > the *_destroy() functions get called a second time in caller functions. > Remove the first calls and let the callers clean it. > > Suggested-by: Ondrej Mosnacek <omosnace@redhat.com> > Signed-off-by: Vratislav Bendel <vbendel@redhat.com> > --- > security/selinux/ss/conditional.c | 20 ++++++-------------- > 1 file changed, 6 insertions(+), 14 deletions(-) > > diff --git a/security/selinux/ss/conditional.c b/security/selinux/ss/conditional.c > index 8bc16ad3af9e..c333daaeceab 100644 > --- a/security/selinux/ss/conditional.c > +++ b/security/selinux/ss/conditional.c > @@ -432,19 +432,16 @@ int cond_read_list(struct policydb *p, void *fp) > > rc = avtab_alloc(&(p->te_cond_avtab), p->te_avtab.nel); > if (rc) > - goto err; > + return rc; > > p->cond_list_len = len; > > for (i = 0; i < len; i++) { > rc = cond_read_node(p, &p->cond_list[i], fp); > if (rc) > - goto err; > + return rc; > } > return 0; > -err: > - cond_list_destroy(p); > - return rc; > } I tend to prefer functions that cleanup their own allocations on error. It makes it easier and quicker to reason about a function's error handling. I recognize in this case it may mean multiple calls to cond_list_destroy(), but that should be safe (considering the previous patches in this series), and we are on the error path anyway so I'm not as worried about a few extra instructions.
diff --git a/security/selinux/ss/conditional.c b/security/selinux/ss/conditional.c index 8bc16ad3af9e..c333daaeceab 100644 --- a/security/selinux/ss/conditional.c +++ b/security/selinux/ss/conditional.c @@ -432,19 +432,16 @@ int cond_read_list(struct policydb *p, void *fp) rc = avtab_alloc(&(p->te_cond_avtab), p->te_avtab.nel); if (rc) - goto err; + return rc; p->cond_list_len = len; for (i = 0; i < len; i++) { rc = cond_read_node(p, &p->cond_list[i], fp); if (rc) - goto err; + return rc; } return 0; -err: - cond_list_destroy(p); - return rc; } int cond_write_bool(void *vkey, void *datum, void *ptr) @@ -643,7 +640,7 @@ static int duplicate_policydb_cond_list(struct policydb *newp, sizeof(*newp->cond_list), GFP_KERNEL); if (!newp->cond_list) - goto error; + return -ENOMEM; for (i = 0; i < origp->cond_list_len; i++) { struct cond_node *newn = &newp->cond_list[i]; @@ -656,27 +653,22 @@ static int duplicate_policydb_cond_list(struct policydb *newp, orign->expr.len * sizeof(*orign->expr.nodes), GFP_KERNEL); if (!newn->expr.nodes) - goto error; + return -ENOMEM; newn->expr.len = orign->expr.len; rc = cond_dup_av_list(&newn->true_list, &orign->true_list, &newp->te_cond_avtab); if (rc) - goto error; + return rc; rc = cond_dup_av_list(&newn->false_list, &orign->false_list, &newp->te_cond_avtab); if (rc) - goto error; + return rc; } return 0; - -error: - avtab_destroy(&newp->te_cond_avtab); - cond_list_destroy(newp); - return -ENOMEM; } static int cond_bools_destroy(void *key, void *datum, void *args)