From b305f7ed0f4f494ad6f3ef5667501535d5a8fa31 Mon Sep 17 00:00:00 2001 From: Yi Wang Date: Wed, 25 Jul 2018 10:26:19 +0800 Subject: audit: fix potential null dereference 'context->module.name' 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. Another one more thing this patch does is using kstrdup instead of (kmalloc + strcpy), and signal a lost record via audit_log_lost. Cc: stable@vger.kernel.org # 4.11 Signed-off-by: Yi Wang Reviewed-by: Jiang Biao Reviewed-by: Richard Guy Briggs Signed-off-by: Paul Moore --- kernel/auditsc.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'kernel/auditsc.c') diff --git a/kernel/auditsc.c b/kernel/auditsc.c index ceb1c4596c51..80d672a11088 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1279,8 +1279,12 @@ 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); @@ -2411,8 +2415,9 @@ void __audit_log_kern_module(char *name) { struct audit_context *context = audit_context(); - context->module.name = kmalloc(strlen(name) + 1, GFP_KERNEL); - strcpy(context->module.name, name); + context->module.name = kstrdup(name, GFP_KERNEL); + if (!context->module.name) + audit_log_lost("out of memory in __audit_log_kern_module"); context->type = AUDIT_KERN_MODULE; } -- cgit