4.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jason Wang jasowang@redhat.com
commit 6e6e41c3112276288ccaf80c70916779b84bb276 upstream.
To avoid slab to warn about exceeded size, fail early if queue occupies more than KMALLOC_MAX_SIZE.
Reported-by: syzbot+e4d4f9ddd4295539735d@syzkaller.appspotmail.com Fixes: 2e0ab8ca83c12 ("ptr_ring: array based FIFO for pointers") Signed-off-by: Jason Wang jasowang@redhat.com Acked-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- include/linux/ptr_ring.h | 2 ++ 1 file changed, 2 insertions(+)
--- a/include/linux/ptr_ring.h +++ b/include/linux/ptr_ring.h @@ -453,6 +453,8 @@ static inline int ptr_ring_consume_batch
static inline void **__ptr_ring_init_queue_alloc(unsigned int size, gfp_t gfp) { + if (size * sizeof(void *) > KMALLOC_MAX_SIZE) + return NULL; return kcalloc(size, sizeof(void *), gfp); }