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authorOndrej Mosnacek <omosnace@redhat.com>2019-03-17 14:46:53 +0100
committerPaul Moore <paul@paul-moore.com>2019-03-18 17:19:48 +0100
commit6a1afffb08ce5f9fb9ccc20f7ab24846c0142984 (patch)
tree960c8d62d8a57248005a8f626b79b4eb37d53dea /security/selinux/ss/policydb.c
parentLinux 5.1-rc1 (diff)
downloadlinux-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/ss/policydb.c')
-rw-r--r--security/selinux/ss/policydb.c13
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)