diff options
| author | Mike Christie <michael.christie@oracle.com> | 2023-10-12 10:05:59 -0500 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-10-17 08:27:24 -0600 |
| commit | 56974c07f2c77d302fc311b0c6b95f45be76a3ae (patch) | |
| tree | 666bc36eacf54488d18e783e17bba23fdac0e312 /drivers/block | |
| parent | d451fdd0fe8323bf970b735cf276d4e11ae8cdcc (diff) | |
ublk: Limit dev_id/ub_number values
The dev_id/ub_number is used for the ublk dev's char device's minor
number so it has to fit into MINORMASK. This patch adds checks to prevent
userspace from passing a number that's too large and limits what can be
allocated by the ublk_index_idr for the case where userspace has the
kernel allocate the dev_id/ub_number.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20231012150600.6198-2-michael.christie@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/ublk_drv.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 630ddfe6657b..ba7c6f9ee136 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -470,6 +470,7 @@ static DEFINE_MUTEX(ublk_ctl_mutex); * It can be extended to one per-user limit in future or even controlled * by cgroup. */ +#define UBLK_MAX_UBLKS UBLK_MINORS static unsigned int ublks_max = 64; static unsigned int ublks_added; /* protected by ublk_ctl_mutex */ @@ -2026,7 +2027,8 @@ static int ublk_alloc_dev_number(struct ublk_device *ub, int idx) if (err == -ENOSPC) err = -EEXIST; } else { - err = idr_alloc(&ublk_index_idr, ub, 0, 0, GFP_NOWAIT); + err = idr_alloc(&ublk_index_idr, ub, 0, UBLK_MAX_UBLKS, + GFP_NOWAIT); } spin_unlock(&ublk_idr_lock); @@ -2305,6 +2307,12 @@ static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd) return -EINVAL; } + if (header->dev_id != U32_MAX && header->dev_id >= UBLK_MAX_UBLKS) { + pr_warn("%s: dev id is too large. Max supported is %d\n", + __func__, UBLK_MAX_UBLKS - 1); + return -EINVAL; + } + ublk_dump_dev_info(&info); ret = mutex_lock_killable(&ublk_ctl_mutex); |