Re: [PATCH] audit: fix potential null dereference 'context->module.name'
Would it make more sense to actually check for failure on allocation
rather than try to remember to deal with it later? How about we just
have audit_log_kern_module return an error and fail if we are OOM?
(also this seems like a good place to use kstrdup, instead of
kmalloc+strcpy)
On Tue, 2018-07-24 at 13:57 +0800, Yi Wang wrote:
The variable 'context->module.name' may be null pointer
when
kmalloc return null, so it's better to check it before using
to avoid null dereference.
Signed-off-by: Yi Wang <wang.yi59(a)zte.com.cn>
Reviewed-by: Jiang Biao <jiang.biao2(a)zte.com.cn>
---
kernel/auditsc.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index e80459f..4830b83 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1272,8 +1272,12 @@ static void show_special(struct audit_context
*context, int *call_panic)
break;
case AUDIT_KERN_MODULE:
audit_log_format(ab, "name=");
- audit_log_untrustedstring(ab, context->module.name);
- kfree(context->module.name);
+ if (context->module.name) {
+ audit_log_untrustedstring(ab, context-
>module.name);
+ kfree(context->module.name);
+ } else
+ audit_log_format(ab, "(null)");
+
break;
}
audit_log_end(ab);
@@ -2409,7 +2413,8 @@ void __audit_log_kern_module(char *name)
struct audit_context *context = current->audit_context;
context->module.name = kmalloc(strlen(name) + 1, GFP_KERNEL);
- strcpy(context->module.name, name);
+ if (context->module.name)
+ strcpy(context->module.name, name);
context->type = AUDIT_KERN_MODULE;
}