| Message ID | 20220202112511.18010-1-vbendel@redhat.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Paul Moore |
| Headers | show |
| Series | [v2] selinux: fix double free of cond_list on error paths | expand |
On Wed, Feb 2, 2022 at 6:25 AM <vbendel@redhat.com> wrote: > > From: Vratislav Bendel <vbendel@redhat.com> > > On error path from cond_read_list() and duplicate_policydb_cond_list() > the cond_list_destroy() gets called a second time in caller functions, > resulting in NULL pointer deref. > Fix this by resetting the cond_list_len to 0 in cond_list_destroy(), > making subsequent calls a noop. > > Also consistently reset the cond_list pointer to NULL after freeing. > > Signed-off-by: Vratislav Bendel <vbendel@redhat.com> > --- > security/selinux/ss/conditional.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) I just merged this into selinux/stable-5.17 and I'll plan on sending this up to Linus tomorrow, thanks Vratislav.
diff --git a/security/selinux/ss/conditional.c b/security/selinux/ss/conditional.c index 2ec6e5cd25d9..feb206f3acb4 100644 --- a/security/selinux/ss/conditional.c +++ b/security/selinux/ss/conditional.c @@ -152,6 +152,8 @@ static void cond_list_destroy(struct policydb *p) for (i = 0; i < p->cond_list_len; i++) cond_node_destroy(&p->cond_list[i]); kfree(p->cond_list); + p->cond_list = NULL; + p->cond_list_len = 0; } void cond_policydb_destroy(struct policydb *p) @@ -441,7 +443,6 @@ int cond_read_list(struct policydb *p, void *fp) return 0; err: cond_list_destroy(p); - p->cond_list = NULL; return rc; }