Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sebastian Ott , Martin Schwidefsky Subject: [PATCH 3.19 059/123] s390/pci: fix possible information leak in mmio syscall Date: Tue, 24 Mar 2015 16:46:08 +0100 Message-Id: <20150324154426.739194292@linuxfoundation.org> In-Reply-To: <20150324154423.655554012@linuxfoundation.org> References: <20150324154423.655554012@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Ott commit f0483044c1c96089256cda4cf182eea1ead77fe4 upstream. Make sure that even in error situations we do not use copy_to_user on uninitialized kernel memory. Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman --- arch/s390/pci/pci_mmio.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) --- a/arch/s390/pci/pci_mmio.c +++ b/arch/s390/pci/pci_mmio.c @@ -64,8 +64,7 @@ SYSCALL_DEFINE3(s390_pci_mmio_write, uns if (copy_from_user(buf, user_buffer, length)) goto out; - memcpy_toio(io_addr, buf, length); - ret = 0; + ret = zpci_memcpy_toio(io_addr, buf, length); out: if (buf != local_buf) kfree(buf); @@ -98,16 +97,16 @@ SYSCALL_DEFINE3(s390_pci_mmio_read, unsi goto out; io_addr = (void *)((pfn << PAGE_SHIFT) | (mmio_addr & ~PAGE_MASK)); - ret = -EFAULT; - if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE) + if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE) { + ret = -EFAULT; goto out; - - memcpy_fromio(buf, io_addr, length); - - if (copy_to_user(user_buffer, buf, length)) + } + ret = zpci_memcpy_fromio(buf, io_addr, length); + if (ret) goto out; + if (copy_to_user(user_buffer, buf, length)) + ret = -EFAULT; - ret = 0; out: if (buf != local_buf) kfree(buf);