[PATCH] kallsyms: Use bounded strnchr() when parsing string

From: Naveen N. Rao
Date: Sun Apr 23 2017 - 13:25:01 EST


When parsing for the <module:name> format, we use strchr() to look for
the separator, when we know that the module name can't be longer than
MODULE_NAME_LEN. Enforce the same using strnchr().

Signed-off-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
---
kernel/module.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/module.c b/kernel/module.c
index 7eba6dea4f41..d3bd56ed3541 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4017,7 +4017,7 @@ unsigned long module_kallsyms_lookup_name(const char *name)

/* Don't lock: we're in enough trouble already. */
preempt_disable();
- if ((colon = strchr(name, ':')) != NULL) {
+ if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
if ((mod = find_module_all(name, colon - name, false)) != NULL)
ret = mod_find_symname(mod, colon+1);
} else {
--
2.12.1