From 2d786e66c9662d84cbeab981ce3a371d2fb5a4bb Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Tue, 18 Apr 2023 21:18:10 +0800 Subject: block: ublk: switch to ioctl command encoding All ublk commands(control, IO) should have taken ioctl command encoding from the beginning, because ioctl command encoding defines each code uniquely, so driver can figure out wrong command sent from userspace easily; 2) it might help security subsystem for audit uring cmd[1]. Unfortunately we didn't do that way, and it could be one lesson for ublk driver. So switch to ioctl command encoding now, we still support commands encoded in old way, but they become legacy definition. Any new command should take ioctl encoding. See ublksrv code for switching to ioctl command encoding in [2]. [1] https://lore.kernel.org/io-uring/CAHC9VhSVzujW9LOj5Km80AjU0EfAuukoLrxO6BEfnXeK_s6bAg@mail.gmail.com/ [2] https://github.com/ming1/ubdsrv/commits/ioctl_cmd_encoding Cc: Christoph Hellwig Cc: Ken Kurematsu Signed-off-by: Ming Lei Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230418131810.855959-1-ming.lei@redhat.com Signed-off-by: Jens Axboe --- drivers/block/Kconfig | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'drivers/block/Kconfig') diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig index f79f20430ef7..5b9d4aaebb81 100644 --- a/drivers/block/Kconfig +++ b/drivers/block/Kconfig @@ -385,6 +385,23 @@ config BLK_DEV_UBLK can handle batch more effectively, but task_work_add() isn't exported for module, so ublk has to be built to kernel. +config BLKDEV_UBLK_LEGACY_OPCODES + bool "Support legacy command opcode" + depends on BLK_DEV_UBLK + default y + help + ublk driver started to take plain command encoding, which turns out + one bad way. The traditional ioctl command opcode encodes more + info and basically defines each code uniquely, so opcode conflict + is avoided, and driver can handle wrong command easily, meantime it + may help security subsystem to audit io_uring command. + + Say Y if your application still uses legacy command opcode. + + Say N if you don't want to support legacy command opcode. It is + suggested to enable N if your application(ublk server) switches to + ioctl command encoding. + source "drivers/block/rnbd/Kconfig" endif # BLK_DEV -- cgit v1.2.3