scsi: Lock down the eata driver

When the kernel is running in secure boot mode, we lock down the kernel to
prevent userspace from modifying the running kernel image.  Whilst this
includes prohibiting access to things like /dev/mem, it must also prevent
access by means of configuring driver modules in such a way as to cause a
device to access or modify the kernel image.

The eata driver takes a single string parameter that contains a slew of
settings, including hardware resource configuration.  Prohibit use of the
parameter if the kernel is locked down.

Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Dario Ballabio <ballabio_dario@emc.com>
cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
cc: "Martin K. Petersen" <martin.petersen@oracle.com>
cc: linux-scsi@vger.kernel.org

Gbp-Pq: Topic features/all/lockdown
Gbp-Pq: Name 0019-scsi-Lock-down-the-eata-driver.patch

diff --git a/drivers/scsi/eata.c b/drivers/scsi/eata.c
index 6501c330d8c84b6f977c8bd1b3364c885194093e..72fceaa8f3da16255080cf204df8d09207794a9e 100644 (file)
--- a/drivers/scsi/eata.c
+++ b/drivers/scsi/eata.c
@@ -1552,8 +1552,11 @@ static int eata2x_detect(struct scsi_host_template *tpnt)
 
        tpnt->proc_name = "eata2x";
 
-       if (strlen(boot_options))
+       if (strlen(boot_options)) {
+               if (kernel_is_locked_down("Command line-specified device addresses, irqs and dma channels"))
+                       return -EPERM;
                option_setup(boot_options);
+       }
 
 #if defined(MODULE)
        /* io_port could have been modified when loading as a module */