On 7/10/19 4:57 PM, Michal Privoznik wrote:
> When creating the admin queue in nvme_init() the variable that
> holds the number of queues created is modified before actual
> queue creation. This is a problem because if creating the queue
> fails then the variable is left in inconsistent state. This was
> actually observed when I tried to hotplug a nvme disk. The
> control got to nvme_file_open() which called nvme_init() which
> failed and thus nvme_close() was called which in turn called
> nvme_free_queue_pair() with queue being NULL. This lead to an
> instant crash:
>
> #0 0x000055d9507ec211 in nvme_free_queue_pair (bs=0x55d952ddb880, q=0x0)
> at block/nvme.c:164
> #1 0x000055d9507ee180 in nvme_close (bs=0x55d952ddb880) at block/nvme.c:729
> #2 0x000055d9507ee3d5 in nvme_file_open (bs=0x55d952ddb880,
> options=0x55d952bb1410, flags=147456, errp=0x7ffd8e19e200) at block/nvme.c:781
> #3 0x000055d9507629f3 in bdrv_open_driver (bs=0x55d952ddb880,
> drv=0x55d95109c1e0 <bdrv_nvme>, node_name=0x0, options=0x55d952bb1410,
> open_flags=147456, errp=0x7ffd8e19e310) at block.c:1291
> #4 0x000055d9507633d6 in bdrv_open_common (bs=0x55d952ddb880, file=0x0,
> options=0x55d952bb1410, errp=0x7ffd8e19e310) at block.c:1551
> #5 0x000055d950766881 in bdrv_open_inherit (filename=0x0, reference=0x0,
> options=0x55d952bb1410, flags=32768, parent=0x55d9538ce420,
> child_role=0x55d950eaade0 <child_file>, errp=0x7ffd8e19e510) at block.c:3063
> #6 0x000055d950765ae4 in bdrv_open_child_bs (filename=0x0,
> options=0x55d9541cdff0, bdref_key=0x55d950af33aa "file",
> parent=0x55d9538ce420, child_role=0x55d950eaade0 <child_file>,
> allow_none=true, errp=0x7ffd8e19e510) at block.c:2712
> #7 0x000055d950766633 in bdrv_open_inherit (filename=0x0, reference=0x0,
> options=0x55d9541cdff0, flags=0, parent=0x0, child_role=0x0,
> errp=0x7ffd8e19e908) at block.c:3011
> #8 0x000055d950766dba in bdrv_open (filename=0x0, reference=0x0,
> options=0x55d953d00390, flags=0, errp=0x7ffd8e19e908) at block.c:3156
> #9 0x000055d9507cb635 in blk_new_open (filename=0x0, reference=0x0,
> options=0x55d953d00390, flags=0, errp=0x7ffd8e19e908) at
> block/block-backend.c:389
> #10 0x000055d950465ec5 in blockdev_init (file=0x0, bs_opts=0x55d953d00390,
> errp=0x7ffd8e19e908) at blockdev.c:602
>
Fixes: bdd6a90a9e5
> Signed-off-by: Michal Privoznik <mpriv...@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
Tested-by: Philippe Mathieu-Daudé <phi...@redhat.com>
> ---
> block/nvme.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/block/nvme.c b/block/nvme.c
> index 73ed5fa75f..9896b7f7c6 100644
> --- a/block/nvme.c
> +++ b/block/nvme.c
> @@ -613,12 +613,12 @@ static int nvme_init(BlockDriverState *bs, const char
> *device, int namespace,
>
> /* Set up admin queue. */
> s->queues = g_new(NVMeQueuePair *, 1);
> - s->nr_queues = 1;
> s->queues[0] = nvme_create_queue_pair(bs, 0, NVME_QUEUE_SIZE, errp);
> if (!s->queues[0]) {
> ret = -EINVAL;
> goto out;
> }
> + s->nr_queues = 1;
> QEMU_BUILD_BUG_ON(NVME_QUEUE_SIZE & 0xF000);
> s->regs->aqa = cpu_to_le32((NVME_QUEUE_SIZE << 16) | NVME_QUEUE_SIZE);
> s->regs->asq = cpu_to_le64(s->queues[0]->sq.iova);
>
