Jonghwan Choi <jhbird.choi@xxxxxxxxxxx> writes: > This patch looks like it should be in the 3.11-stable tree, should we apply > it? Well, do you think a kmemleak false positive which has been around for years, and was only just noticed now, is suddenly important? If so, I need to send a lot more patches to stable. In fact, since every patch I submit should be an improvement to the kernel, I'll have to CC stable on every patch! Rusty. > ------------------ > > From: "Rusty Russell <rusty@xxxxxxxxxxxxxxx>" > > commit bb478d8b167cf875565ac7d927ffbdc0b6d280e8 upstream > > unreferenced object 0xffff88003d467e20 (size 32): > comm "softirq", pid 0, jiffies 4295197765 (age 6.364s) > hex dump (first 32 bytes): > 28 19 bf 3d 00 00 00 00 0c 00 00 00 01 00 01 00 (..=............ > 02 dc 51 3c 00 00 00 00 56 00 00 00 00 00 00 00 ..Q<....V....... > backtrace: > [<ffffffff8152db19>] kmemleak_alloc+0x59/0xc0 > [<ffffffff81102e93>] __kmalloc+0xf3/0x180 > [<ffffffff812db5d6>] vring_add_indirect+0x36/0x280 > [<ffffffff812dc59f>] virtqueue_add_outbuf+0xbf/0x4e0 > [<ffffffff813a8b30>] start_xmit+0x1a0/0x3b0 > [<ffffffff81445861>] dev_hard_start_xmit+0x2d1/0x4d0 > [<ffffffff81460052>] sch_direct_xmit+0xf2/0x1c0 > [<ffffffff81445c28>] dev_queue_xmit+0x1c8/0x460 > [<ffffffff814e3187>] ip6_finish_output2+0x1d7/0x470 > [<ffffffff814e34b0>] ip6_finish_output+0x90/0xb0 > [<ffffffff814e3507>] ip6_output+0x37/0xb0 > [<ffffffff815021eb>] igmp6_send+0x2db/0x470 > [<ffffffff81502645>] igmp6_timer_handler+0x95/0xa0 > [<ffffffff8104b57c>] call_timer_fn+0x2c/0x90 > [<ffffffff8104b7ba>] run_timer_softirq+0x1da/0x1f0 > [<ffffffff81045721>] __do_softirq+0xd1/0x1b0 > > Address gets embedded in a descriptor via virt_to_phys(). See detach_buf, > which frees it: > > if (vq->vring.desc[i].flags & VRING_DESC_F_INDIRECT) > kfree(phys_to_virt(vq->vring.desc[i].addr)); > > Reported-by: Christoph Paasch <christoph.paasch@xxxxxxxxxxxx> > Fix-suggested-by: Christoph Paasch <christoph.paasch@xxxxxxxxxxxx> > Typing-done-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx> > Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx> > Signed-off-by: Jonghwan Choi <jhbird.choi@xxxxxxxxxxx> > --- > drivers/virtio/virtio_ring.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index 6b4a4db..6547d46 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -173,6 +173,8 @@ static inline int vring_add_indirect(struct > vring_virtqueue *vq, > head = vq->free_head; > vq->vring.desc[head].flags = VRING_DESC_F_INDIRECT; > vq->vring.desc[head].addr = virt_to_phys(desc); > + /* kmemleak gives a false positive, as it's hidden by virt_to_phys > */ > + kmemleak_ignore(desc); > vq->vring.desc[head].len = i * sizeof(struct vring_desc); > > /* Update free pointer */ > -- > 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html