diff options
Diffstat (limited to 'CVE-2017-1000364.mm-fix-new-crash-in-unmapped_area_topdown.patch')
| -rw-r--r-- | CVE-2017-1000364.mm-fix-new-crash-in-unmapped_area_topdown.patch | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/CVE-2017-1000364.mm-fix-new-crash-in-unmapped_area_topdown.patch b/CVE-2017-1000364.mm-fix-new-crash-in-unmapped_area_topdown.patch new file mode 100644 index 000000000000..25fc3f55d6e9 --- /dev/null +++ b/CVE-2017-1000364.mm-fix-new-crash-in-unmapped_area_topdown.patch @@ -0,0 +1,47 @@ +From f4cb767d76cf7ee72f97dd76f6cfa6c76a5edc89 Mon Sep 17 00:00:00 2001 +From: Hugh Dickins <hughd@google.com> +Date: Tue, 20 Jun 2017 02:10:44 -0700 +Subject: [PATCH] mm: fix new crash in unmapped_area_topdown() + +Trinity gets kernel BUG at mm/mmap.c:1963! in about 3 minutes of +mmap testing. That's the VM_BUG_ON(gap_end < gap_start) at the +end of unmapped_area_topdown(). Linus points out how MAP_FIXED +(which does not have to respect our stack guard gap intentions) +could result in gap_end below gap_start there. Fix that, and +the similar case in its alternative, unmapped_area(). + +Cc: stable@vger.kernel.org +Fixes: 1be7107fbe18 ("mm: larger stack guard gap, between vmas") +Reported-by: Dave Jones <davej@codemonkey.org.uk> +Debugged-by: Linus Torvalds <torvalds@linux-foundation.org> +Signed-off-by: Hugh Dickins <hughd@google.com> +Acked-by: Michal Hocko <mhocko@suse.com> +Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> +--- + mm/mmap.c | 6 ++++-- + 1 file changed, 4 insertions(+), 2 deletions(-) + +diff --git a/mm/mmap.c b/mm/mmap.c +index 8e07976d5e477..290b77d9a01e0 100644 +--- a/mm/mmap.c ++++ b/mm/mmap.c +@@ -1817,7 +1817,8 @@ unsigned long unmapped_area(struct vm_unmapped_area_info *info) + /* Check if current node has a suitable gap */ + if (gap_start > high_limit) + return -ENOMEM; +- if (gap_end >= low_limit && gap_end - gap_start >= length) ++ if (gap_end >= low_limit && ++ gap_end > gap_start && gap_end - gap_start >= length) + goto found; + + /* Visit right subtree if it looks promising */ +@@ -1920,7 +1921,8 @@ unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info) + gap_end = vm_start_gap(vma); + if (gap_end < low_limit) + return -ENOMEM; +- if (gap_start <= high_limit && gap_end - gap_start >= length) ++ if (gap_start <= high_limit && ++ gap_end > gap_start && gap_end - gap_start >= length) + goto found; + + /* Visit left subtree if it looks promising */ |