Re: [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&gt; --- 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 -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility