[v17,9/9] of: fdt: fix memory address be truncated

Message ID 1407408695-19626-10-git-send-email-haojian.zhuang@linaro.org
State New
Headers show

Commit Message

Haojian Zhuang Aug. 7, 2014, 10:51 a.m.
early_init_dt_add_memory_arch() accepts base & size parameters as u64
type. memblock_add() accepts base & size parameters as phys_addr_t type.
But phys_addr_t isn't equal to u64. In 32-bit system, phys_addr_t is
32-bit long. If 64-bit memory address is specified in DTS file, it'll be
truncated into 32-bit address.

So create two values to store base & size first as phys_addr_t type.
Then compare them with u64 base & u64 size. If they don't match, discard
them.

Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
---
 drivers/of/fdt.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Rob Herring Aug. 7, 2014, 1:30 p.m. | #1
On Thu, Aug 7, 2014 at 5:51 AM, Haojian Zhuang
<haojian.zhuang@linaro.org> wrote:
> early_init_dt_add_memory_arch() accepts base & size parameters as u64
> type. memblock_add() accepts base & size parameters as phys_addr_t type.
> But phys_addr_t isn't equal to u64. In 32-bit system, phys_addr_t is
> 32-bit long. If 64-bit memory address is specified in DTS file, it'll be
> truncated into 32-bit address.
>
> So create two values to store base & size first as phys_addr_t type.
> Then compare them with u64 base & u64 size. If they don't match, discard
> them.

This is fixed already in v3.16:

commit a67a6ed15513541579d38bcbd127e7be170710e5
Author: Laura Abbott <lauraa@codeaurora.org>
Date:   Thu Jun 19 20:13:38 2014 -0700

    of: Check for phys_addr_t overflows in early_init_dt_add_memory_arch

    The common early_init_dt_add_memory_arch takes the base and size
    of a memory region as u64 types. The function never checks if
    the base and size can actually fit in a phys_addr_t which may
    be smaller than 64-bits. This may result in incorrect memory
    being passed to memblock_add if the memory falls outside the
    range of phys_addr_t. Add range checks for the base and size if
    phys_addr_t is smaller than u64.

    Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
    Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
    Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
    Acked-by: Nicolas Pitre <nico@linaro.org>
    Signed-off-by: Grant Likely <grant.likely@linaro.org>


In the future, please use get_maintainers.pl to cc the correct people.

Rob

Patch

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index c4cddf0..10d5382 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -878,6 +878,8 @@  int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
 {
 	const u64 phys_offset = __pa(PAGE_OFFSET);
+	phys_addr_t mbase, msize;
+
 	base &= PAGE_MASK;
 	size &= PAGE_MASK;
 	if (base + size < phys_offset) {
@@ -885,6 +887,14 @@  void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
 			   base, base + size);
 		return;
 	}
+	/* phys_addr_t may not be equal to u64 */
+	mbase = base;
+	msize = size;
+	if ((mbase != base) || (msize != size)) {
+		pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
+			   base, base + size);
+		return;
+	}
 	if (base < phys_offset) {
 		pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
 			   base, phys_offset);