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authorLaura Abbott <labbott@fedoraproject.org>2017-06-20 08:37:17 -0700
committerLaura Abbott <labbott@fedoraproject.org>2017-06-20 08:38:21 -0700
commitebe6d67223a824259cea9bae73568adcf1a8d2f7 (patch)
tree907c545a6a47ae00ea22c511584d56ab61fb571d
parentd1444500d9cabf7618723b79a898c0ed08b91486 (diff)
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Add fix for stackguard
-rw-r--r--kernel.spec1
-rw-r--r--mm-fix-new-crash-in-unmapped_area_topdown.patch53
2 files changed, 54 insertions, 0 deletions
diff --git a/kernel.spec b/kernel.spec
index 59100c06a..77bc70ef7 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -637,6 +637,7 @@ Patch683: RFC-audit-fix-a-race-condition-with-the-auditd-tracking-code.patch
# CVE-2017-1000364 rhbz 1462819 1461333
Patch684: mm-larger-stack-guard-gap-between-vmas.patch
+Patch685: mm-fix-new-crash-in-unmapped_area_topdown.patch
# END OF PATCH DEFINITIONS
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
index 000000000..20da9556f
--- /dev/null
+++ b/mm-fix-new-crash-in-unmapped_area_topdown.patch
@@ -0,0 +1,53 @@
+From patchwork Tue Jun 20 09:10:44 2017
+Content-Type: text/plain; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 7bit
+Subject: mm: fix new crash in unmapped_area_topdown()
+From: Hugh Dickins <hughd@google.com>
+X-Patchwork-Id: 9798991
+Message-Id: <alpine.LSU.2.11.1706200206210.10925@eggly.anvils>
+To: Linus Torvalds <torvalds@linux-foundation.org>
+Cc: Dave Jones <davej@codemonkey.org.uk>, Oleg Nesterov <oleg@redhat.com>,
+ Michal Hocko <mhocko@suse.com>, linux-kernel@vger.kernel.org,
+ linux-mm@kvack.org
+Date: Tue, 20 Jun 2017 02:10:44 -0700 (PDT)
+
+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>
+---
+
+ mm/mmap.c | 6 ++++--
+ 1 file changed, 4 insertions(+), 2 deletions(-)
+
+--- 4.12-rc6/mm/mmap.c 2017-06-19 09:06:10.035407505 -0700
++++ linux/mm/mmap.c 2017-06-19 21:09:28.616707311 -0700
+@@ -1817,7 +1817,8 @@ unsigned long unmapped_area(struct vm_un
+ /* 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(stru
+ 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 */