Re: [PATCH] ublk: fix NULL pointer dereference in ublk_ctrl_set_size()

[Jens Axboe]

On Thu, 05 Mar 2026 14:31:46 -0500, Mehul Rao wrote:
> ublk_ctrl_set_size() unconditionally dereferences ub->ub_disk via
> set_capacity_and_notify() without checking if it is NULL.
> 
> ub->ub_disk is NULL before UBLK_CMD_START_DEV completes (it is only
> assigned in ublk_ctrl_start_dev()) and after UBLK_CMD_STOP_DEV runs
> (ublk_detach_disk() sets it to NULL). Since the UBLK_CMD_UPDATE_SIZE
> handler performs no state validation, a user can trigger a NULL pointer
> dereference by sending UPDATE_SIZE to a device that has been added but
> not yet started, or one that has been stopped.
> 
> [...]

Applied, thanks!

[1/1] ublk: fix NULL pointer dereference in ublk_ctrl_set_size()
      commit: 25966fc097691e5c925ad080f64a2f19c5fd940a

Best regards,
-- 
Jens Axboe