[Crash-utility] [PATCH] Fix incorrect hstate pointer arithmetic in "kmem -i" command
Without this patch we may access an arbitrary address and report an
incorrect total huge pages value.
Signed-off-by: Aaron Tomlin <atomlin(a)redhat.com>
---
memory.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/memory.c b/memory.c
index 72218e7..613add7 100644
--- a/memory.c
+++ b/memory.c
@@ -15207,7 +15207,7 @@ next_physpage(ulonglong paddr, ulonglong *nextpaddr)
static int
get_hugetlb_total_pages(ulong *nr_total_pages)
{
- ulong hstate_p;
+ ulong hstate_p, vaddr;
int i, len;
ulong nr_huge_pages;
uint horder;
@@ -15224,13 +15224,16 @@ get_hugetlb_total_pages(ulong *nr_total_pages)
hstate_p = symbol_value("hstates");
for (i = 0; i < len; i++) {
- hstate_p = hstate_p + (SIZE(hstate) * i);
+ vaddr = hstate_p + (SIZE(hstate) * i);
- readmem(hstate_p + OFFSET(hstate_order),
+ readmem(vaddr + OFFSET(hstate_order),
KVADDR, &horder, sizeof(uint),
"hstate_order", FAULT_ON_ERROR);
- readmem(hstate_p + OFFSET(hstate_nr_huge_pages),
+ if (!horder)
+ continue;
+
+ readmem(vaddr + OFFSET(hstate_nr_huge_pages),
KVADDR, &nr_huge_pages, sizeof(ulong),
"hstate_nr_huge_pages", FAULT_ON_ERROR);
--
2.4.3