| Message ID | 0100016819f5682e-a7e2541c-4390-4e14-ac65-8793243215c6-000000@email.amazonses.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [FIX] slab: Alien caches must not be initialized if the allocation of the alien cache failed | expand |
On Fri, Jan 4, 2019 at 6:42 PM Christopher Lameter <cl@linux.com> wrote: > > From: Christoph Lameter <cl@linux.com> > > Callers of __alloc_alien() check for NULL. > We must do the same check in __alloc_alien() after the allocation of > the alien cache to avoid potential NULL pointer dereferences > should the allocation fail. > > Fixes: 49dfc304ba241b315068023962004542c5118103 ("slab: use the lock on alien_cache, instead of the lock on array_cache") > Fixes: c8522a3a5832b843570a3315674f5a3575958a5 ("Slab: introduce alloc_alien") > Signed-off-by: Christoph Lameter <cl@linux.com> Please also add the Reported-by tag to commit for tracking purposes: Reported-by: syzbot+d6ed4ec679652b4fd4e4@syzkaller.appspotmail.com > Index: linux/mm/slab.c > =================================================================== > --- linux.orig/mm/slab.c > +++ linux/mm/slab.c > @@ -666,8 +666,10 @@ static struct alien_cache *__alloc_alien > struct alien_cache *alc = NULL; > > alc = kmalloc_node(memsize, gfp, node); > - init_arraycache(&alc->ac, entries, batch); > - spin_lock_init(&alc->lock); > + if (alc) { > + init_arraycache(&alc->ac, entries, batch); > + spin_lock_init(&alc->lock); > + } > return alc; > } >
Index: linux/mm/slab.c =================================================================== --- linux.orig/mm/slab.c +++ linux/mm/slab.c @@ -666,8 +666,10 @@ static struct alien_cache *__alloc_alien struct alien_cache *alc = NULL; alc = kmalloc_node(memsize, gfp, node); - init_arraycache(&alc->ac, entries, batch); - spin_lock_init(&alc->lock); + if (alc) { + init_arraycache(&alc->ac, entries, batch); + spin_lock_init(&alc->lock); + } return alc; }