6.6-stable review patch. If anyone has any objections, please let me know.
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From: Ming Lei ming.lei@redhat.com
commit d369735e02ef122d19d4c3d093028da0eb400636 upstream.
In ublk_ch_mmap(), queue id is calculated in the following way:
(vma->vm_pgoff << PAGE_SHIFT) / `max_cmd_buf_size`
'max_cmd_buf_size' is equal to
`UBLK_MAX_QUEUE_DEPTH * sizeof(struct ublksrv_io_desc)`
and UBLK_MAX_QUEUE_DEPTH is 4096 and part of UAPI, so 'max_cmd_buf_size' is always page aligned in 4K page size kernel. However, it isn't true in 64K page size kernel.
Fixes the issue by always rounding up 'max_cmd_buf_size' with PAGE_SIZE.
Cc: stable@vger.kernel.org Fixes: 71f28f3136af ("ublk_drv: add io_uring based userspace block driver") Signed-off-by: Ming Lei ming.lei@redhat.com Link: https://lore.kernel.org/r/20241111110718.1394001-1-ming.lei@redhat.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/block/ublk_drv.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)
--- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -713,12 +713,21 @@ static inline char *ublk_queue_cmd_buf(s return ublk_get_queue(ub, q_id)->io_cmd_buf; }
+static inline int __ublk_queue_cmd_buf_size(int depth) +{ + return round_up(depth * sizeof(struct ublksrv_io_desc), PAGE_SIZE); +} + static inline int ublk_queue_cmd_buf_size(struct ublk_device *ub, int q_id) { struct ublk_queue *ubq = ublk_get_queue(ub, q_id);
- return round_up(ubq->q_depth * sizeof(struct ublksrv_io_desc), - PAGE_SIZE); + return __ublk_queue_cmd_buf_size(ubq->q_depth); +} + +static int ublk_max_cmd_buf_size(void) +{ + return __ublk_queue_cmd_buf_size(UBLK_MAX_QUEUE_DEPTH); }
static inline bool ublk_queue_can_use_recovery_reissue( @@ -1387,7 +1396,7 @@ static int ublk_ch_mmap(struct file *fil { struct ublk_device *ub = filp->private_data; size_t sz = vma->vm_end - vma->vm_start; - unsigned max_sz = UBLK_MAX_QUEUE_DEPTH * sizeof(struct ublksrv_io_desc); + unsigned max_sz = ublk_max_cmd_buf_size(); unsigned long pfn, end, phys_off = vma->vm_pgoff << PAGE_SHIFT; int q_id, ret = 0;