[PATCH 07/12] lkdtm: remove intentional off-by-one array access

From: Kees Cook
Date: Wed Jul 06 2016 - 18:33:56 EST


There wasn't a good reason for keeping the enum and the names out of sync
by 1 position just to avoid "NONE" and "INVALID" from being in the string
lists.

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
drivers/misc/lkdtm_core.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/misc/lkdtm_core.c b/drivers/misc/lkdtm_core.c
index e0f10131511f..4f9d2f32c88b 100644
--- a/drivers/misc/lkdtm_core.c
+++ b/drivers/misc/lkdtm_core.c
@@ -111,6 +111,7 @@ enum ctype {
};

static char* cp_name[] = {
+ "INVALID",
"INT_HARDWARE_ENTRY",
"INT_HW_IRQ_EN",
"INT_TASKLET_ENTRY",
@@ -123,6 +124,7 @@ static char* cp_name[] = {
};

static char* cp_type[] = {
+ "NONE",
"PANIC",
"BUG",
"WARNING",
@@ -257,7 +259,7 @@ static enum ctype parse_cp_type(const char *what, size_t count)

for (i = 0; i < ARRAY_SIZE(cp_type); i++) {
if (!strcmp(what, cp_type[i]))
- return i + 1;
+ return i;
}

return CT_NONE;
@@ -266,9 +268,9 @@ static enum ctype parse_cp_type(const char *what, size_t count)
static const char *cp_type_to_str(enum ctype type)
{
if (type == CT_NONE || type < 0 || type > ARRAY_SIZE(cp_type))
- return "None";
+ return "NONE";

- return cp_type[type - 1];
+ return cp_type[type];
}

static const char *cp_name_to_str(enum cname name)
@@ -276,7 +278,7 @@ static const char *cp_name_to_str(enum cname name)
if (name == CN_INVALID || name < 0 || name > ARRAY_SIZE(cp_name))
return "INVALID";

- return cp_name[name - 1];
+ return cp_name[name];
}


@@ -304,9 +306,13 @@ static int lkdtm_parse_commandline(void)
if (cptype == CT_NONE)
return -EINVAL;

+ /* Refuse INVALID as a selectable crashpoint name. */
+ if (!strcmp(cpoint_name, "INVALID"))
+ return -EINVAL;
+
for (i = 0; i < ARRAY_SIZE(cp_name); i++) {
if (!strcmp(cpoint_name, cp_name[i])) {
- cpoint = i + 1;
+ cpoint = i;
return 0;
}
}
--
2.7.4