4.17-stable review patch. If anyone has any objections, please let me know.
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From: Yi Wang wang.yi59@zte.com.cn
commit b305f7ed0f4f494ad6f3ef5667501535d5a8fa31 upstream.
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 wang.yi59@zte.com.cn Reviewed-by: Jiang Biao jiang.biao2@zte.com.cn Reviewed-by: Richard Guy Briggs rgb@redhat.com Signed-off-by: Paul Moore paul@paul-moore.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/auditsc.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
--- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1274,8 +1274,12 @@ static void show_special(struct audit_co 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); @@ -2408,8 +2412,9 @@ 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); + 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; }