From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756216Ab2C3PEy (ORCPT ); Fri, 30 Mar 2012 11:04:54 -0400 Received: from mail-bk0-f46.google.com ([209.85.214.46]:64101 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751083Ab2C3PEr (ORCPT ); Fri, 30 Mar 2012 11:04:47 -0400 From: Sasha Levin To: arnd@arndb.de, gregkh@linuxfoundation.org, viro@zeniv.linux.org.uk Cc: davej@redhat.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, Sasha Levin Subject: [PATCH] kmsg: Use vmalloc instead of kmalloc when writing Date: Fri, 30 Mar 2012 13:04:27 -0400 Message-Id: <1333127067-2043-1-git-send-email-levinsasha928@gmail.com> X-Mailer: git-send-email 1.7.8.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are no size checks in kmsg_write(), and we try allocating enough memory to store everything userspace gave us, which may be too much for kmalloc to allocate. One option would be to limit it to something, but we can't come up with a number that would make sense. Instead, just use vmalloc so that nothing would break with large amounts of data. Signed-off-by: Sasha Levin --- drivers/char/mem.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/char/mem.c b/drivers/char/mem.c index d6e9d08..e047783 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -815,7 +815,7 @@ static ssize_t kmsg_writev(struct kiocb *iocb, const struct iovec *iv, ssize_t ret = -EFAULT; size_t len = iov_length(iv, count); - line = kmalloc(len + 1, GFP_KERNEL); + line = vmalloc(len + 1); if (line == NULL) return -ENOMEM; @@ -836,7 +836,7 @@ static ssize_t kmsg_writev(struct kiocb *iocb, const struct iovec *iv, if (ret > len) ret = len; out: - kfree(line); + vfree(line); return ret; } -- 1.7.8.4