[PATCH 3.19 059/123] s390/pci: fix possible information leak in mmio syscall
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2015-03-24 17:31:35
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3.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Ott <redacted> 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 <redacted> Signed-off-by: Martin Schwidefsky <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- 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);