add follow-up fix for CVE-2017-100364 fix

diff --git a/Makefile b/Makefile
index 647c4a37f3e035c26a85912acdabc9122c89be0a..d832143dbc5153652c2dbb90dd2870df3af46989 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -243,6 +243,7 @@ ${KERNEL_SRC}/README ${KERNEL_CFG_ORG}: ${KERNEL_SRC_SUBMODULE} | submodules
        cd ${KERNEL_SRC}; patch -p1 < ../CVE-2017-9242-ipv6-fix-out-of-bound-writes-in-__ip6_append_data.patch
        cd ${KERNEL_SRC}; patch -p1 < ../pinctl-amd-ryzen-01-make-use-of-raw_spinlock-variants.patch
        cd ${KERNEL_SRC}; patch -p1 < ../pinctl-amd-ryzen-02-Use-regular-interrupt-instead-of-chained.patch
+       cd ${KERNEL_SRC}; patch -p1 < ../mm-fix-new-crash-in-unmapped_area_topdown.patch
        sed -i ${KERNEL_SRC}/Makefile -e 's/^EXTRAVERSION.*$$/EXTRAVERSION=${EXTRAVERSION}/'
        touch $@
 

diff --git a/mm-fix-new-crash-in-unmapped_area_topdown.patch b/mm-fix-new-crash-in-unmapped_area_topdown.patch
new file mode 100644 (file)
index 0000000..0730092
--- /dev/null
+++ b/mm-fix-new-crash-in-unmapped_area_topdown.patch
@@ -0,0 +1,54 @@
+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()
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+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>
+Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
+---
+ mm/mmap.c | 6 ++++--
+ 1 file changed, 4 insertions(+), 2 deletions(-)
+
+diff --git a/mm/mmap.c b/mm/mmap.c
+index 8e07976d5e47..290b77d9a01e 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 */
+-- 
+2.11.0
+