diff options
| author | Ondrej Mosnacek <omosnace@redhat.com> | 2019-03-17 14:46:53 +0100 |
|---|---|---|
| committer | Paul Moore <paul@paul-moore.com> | 2019-03-18 17:19:48 +0100 |
| commit | 6a1afffb08ce5f9fb9ccc20f7ab24846c0142984 (patch) | |
| tree | 960c8d62d8a57248005a8f626b79b4eb37d53dea /security/selinux | |
| parent | Linux 5.1-rc1 (diff) | |
| download | linux-6a1afffb08ce5f9fb9ccc20f7ab24846c0142984.tar.xz linux-6a1afffb08ce5f9fb9ccc20f7ab24846c0142984.zip | |
selinux: fix NULL dereference in policydb_destroy()
The conversion to kvmalloc() forgot to account for the possibility that
p->type_attr_map_array might be null in policydb_destroy().
Fix this by destroying its contents only if it is not NULL.
Also make sure ebitmap_init() is called on all entries before
policydb_destroy() can be called. Right now this is a no-op, because
both kvcalloc() and ebitmap_init() just zero out the whole struct, but
let's rather not rely on a specific implementation.
Reported-by: syzbot+a57b2aff60832666fc28@syzkaller.appspotmail.com
Fixes: acdf52d97f82 ("selinux: convert to kvmalloc")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Diffstat (limited to 'security/selinux')
| -rw-r--r-- | security/selinux/ss/policydb.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index 6b576e588725..daecdfb15a9c 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -828,9 +828,11 @@ void policydb_destroy(struct policydb *p) hashtab_map(p->range_tr, range_tr_destroy, NULL); hashtab_destroy(p->range_tr); - for (i = 0; i < p->p_types.nprim; i++) - ebitmap_destroy(&p->type_attr_map_array[i]); - kvfree(p->type_attr_map_array); + if (p->type_attr_map_array) { + for (i = 0; i < p->p_types.nprim; i++) + ebitmap_destroy(&p->type_attr_map_array[i]); + kvfree(p->type_attr_map_array); + } ebitmap_destroy(&p->filename_trans_ttypes); ebitmap_destroy(&p->policycaps); @@ -2496,10 +2498,13 @@ int policydb_read(struct policydb *p, void *fp) if (!p->type_attr_map_array) goto bad; + /* just in case ebitmap_init() becomes more than just a memset(0): */ + for (i = 0; i < p->p_types.nprim; i++) + ebitmap_init(&p->type_attr_map_array[i]); + for (i = 0; i < p->p_types.nprim; i++) { struct ebitmap *e = &p->type_attr_map_array[i]; - ebitmap_init(e); if (p->policyvers >= POLICYDB_VERSION_AVTAB) { rc = ebitmap_read(e, fp); if (rc) |