Fix CVE-2017-1000364 by backporting the patches for rpi3

[AGL/meta-agl.git] / meta-agl-bsp / meta-raspberrypi / recipes-kernel / linux / linux-raspberrypi-4.9 / 0003-mm-fix-new-crash-in-unmapped_area_topdown.patch

diff --git a/meta-agl-bsp/meta-raspberrypi/recipes-kernel/linux/linux-raspberrypi-4.9/0003-mm-fix-new-crash-in-unmapped_area_topdown.patch b/meta-agl-bsp/meta-raspberrypi/recipes-kernel/linux/linux-raspberrypi-4.9/0003-mm-fix-new-crash-in-unmapped_area_topdown.patch
new file mode 100644 (file)
index 0000000..7dc7919
--- /dev/null
+++ b/meta-agl-bsp/meta-raspberrypi/recipes-kernel/linux/linux-raspberrypi-4.9/0003-mm-fix-new-crash-in-unmapped_area_topdown.patch
@@ -0,0 +1,52 @@
+From 00d15368d611f12f3c4980dce63b68b08ea89a09 Mon Sep 17 00:00:00 2001
+From: Hugh Dickins <hughd@google.com>
+Date: Tue, 20 Jun 2017 02:10:44 -0700
+Subject: [PATCH 3/3] mm: fix new crash in unmapped_area_topdown()
+
+commit f4cb767d76cf7ee72f97dd76f6cfa6c76a5edc89 upstream.
+
+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().
+
+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>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ mm/mmap.c | 6 ++++--
+ 1 file changed, 4 insertions(+), 2 deletions(-)
+
+diff --git a/mm/mmap.c b/mm/mmap.c
+index d71a61e..145d3d5 100644
+--- a/mm/mmap.c
++++ b/mm/mmap.c
+@@ -1813,7 +1813,8 @@ 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 */
+@@ -1916,7 +1917,8 @@ 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 */
+-- 
+2.1.4
+