From ebe6d67223a824259cea9bae73568adcf1a8d2f7 Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Tue, 20 Jun 2017 08:37:17 -0700 Subject: Add fix for stackguard --- kernel.spec | 1 + mm-fix-new-crash-in-unmapped_area_topdown.patch | 53 +++++++++++++++++++++++++ 2 files changed, 54 insertions(+) create mode 100644 mm-fix-new-crash-in-unmapped_area_topdown.patch 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 +X-Patchwork-Id: 9798991 +Message-Id: +To: Linus Torvalds +Cc: Dave Jones , Oleg Nesterov , + Michal Hocko , 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 +Debugged-by: Linus Torvalds +Signed-off-by: Hugh Dickins +--- + + 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 */ -- cgit