diff options
Diffstat (limited to 'debian/patches/features/all/lockdown/mtd-disable-slram-and-phram-when-locked-down.patch')
| -rw-r--r-- | debian/patches/features/all/lockdown/mtd-disable-slram-and-phram-when-locked-down.patch | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/debian/patches/features/all/lockdown/mtd-disable-slram-and-phram-when-locked-down.patch b/debian/patches/features/all/lockdown/mtd-disable-slram-and-phram-when-locked-down.patch new file mode 100644 index 000000000..c718e7e2f --- /dev/null +++ b/debian/patches/features/all/lockdown/mtd-disable-slram-and-phram-when-locked-down.patch @@ -0,0 +1,75 @@ +From: Ben Hutchings <ben@decadent.org.uk> +Date: Fri, 30 Aug 2019 15:54:24 +0100 +Subject: mtd: phram,slram: Disable when the kernel is locked down +Forwarded: https://lore.kernel.org/linux-security-module/20190830154720.eekfjt6c4jzvlbfz@decadent.org.uk/ + +These drivers allow mapping arbitrary memory ranges as MTD devices. +This should be disabled to preserve the kernel's integrity when it is +locked down. + +* Add the HWPARAM flag to the module parameters +* When slram is built-in, it uses __setup() to read kernel parameters, + so add an explicit check security_locked_down() check + +Signed-off-by: Ben Hutchings <ben@decadent.org.uk> +Cc: Matthew Garrett <mjg59@google.com> +Cc: David Howells <dhowells@redhat.com> +Cc: Joern Engel <joern@lazybastard.org> +Cc: linux-mtd@lists.infradead.org +--- + drivers/mtd/devices/phram.c | 6 +++++- + drivers/mtd/devices/slram.c | 9 ++++++++- + 2 files changed, 13 insertions(+), 2 deletions(-) + +--- a/drivers/mtd/devices/phram.c ++++ b/drivers/mtd/devices/phram.c +@@ -364,7 +364,11 @@ static int phram_param_call(const char * + #endif + } + +-module_param_call(phram, phram_param_call, NULL, NULL, 0200); ++static const struct kernel_param_ops phram_param_ops = { ++ .set = phram_param_call ++}; ++__module_param_call(MODULE_PARAM_PREFIX, phram, &phram_param_ops, NULL, ++ 0200, -1, KERNEL_PARAM_FL_HWPARAM | hwparam_iomem); + MODULE_PARM_DESC(phram, "Memory region to map. \"phram=<name>,<start>,<length>[,<erasesize>]\""); + + #ifdef CONFIG_OF +--- a/drivers/mtd/devices/slram.c ++++ b/drivers/mtd/devices/slram.c +@@ -43,6 +43,7 @@ + #include <linux/ioctl.h> + #include <linux/init.h> + #include <linux/io.h> ++#include <linux/security.h> + + #include <linux/mtd/mtd.h> + +@@ -65,7 +66,7 @@ typedef struct slram_mtd_list { + #ifdef MODULE + static char *map[SLRAM_MAX_DEVICES_PARAMS]; + +-module_param_array(map, charp, NULL, 0); ++module_param_hw_array(map, charp, iomem, NULL, 0); + MODULE_PARM_DESC(map, "List of memory regions to map. \"map=<name>, <start>, <length / end>\""); + #else + static char *map; +@@ -281,11 +282,17 @@ static int __init init_slram(void) + #ifndef MODULE + char *devstart; + char *devlength; ++ int ret; + + if (!map) { + E("slram: not enough parameters.\n"); + return(-EINVAL); + } ++ ++ ret = security_locked_down(LOCKDOWN_MODULE_PARAMETERS); ++ if (ret) ++ return ret; ++ + while (map) { + devname = devstart = devlength = NULL; + |