This is a note to let you know that I've just added the patch titled
mm: fix overflow check in expand_upwards()
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-fix-overflow-check-in-expand_upwards.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 37511fb5c91db93d8bd6e3f52f86e5a7ff7cfcdf Mon Sep 17 00:00:00 2001
From: Helge Deller <deller@xxxxxx>
Date: Fri, 14 Jul 2017 14:49:38 -0700
Subject: mm: fix overflow check in expand_upwards()
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From: Helge Deller <deller@xxxxxx>
commit 37511fb5c91db93d8bd6e3f52f86e5a7ff7cfcdf upstream.
Jörn Engel noticed that the expand_upwards() function might not return
-ENOMEM in case the requested address is (unsigned long)-PAGE_SIZE and
if the architecture didn't defined TASK_SIZE as multiple of PAGE_SIZE.
Affected architectures are arm, frv, m68k, blackfin, h8300 and xtensa
which all define TASK_SIZE as 0xffffffff, but since none of those have
an upwards-growing stack we currently have no actual issue.
Nevertheless let's fix this just in case any of the architectures with
an upward-growing stack (currently parisc, metag and partly ia64) define
TASK_SIZE similar.
Link: http://lkml.kernel.org/r/20170702192452.GA11868@xxxxxxxx
Fixes: bd726c90b6b8 ("Allow stack to grow up to address space limit")
Signed-off-by: Helge Deller <deller@xxxxxx>
Reported-by: Jörn Engel <joern@xxxxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2228,7 +2228,7 @@ int expand_upwards(struct vm_area_struct
/* Guard against exceeding limits of the address space. */
address &= PAGE_MASK;
- if (address >= TASK_SIZE)
+ if (address >= (TASK_SIZE & PAGE_MASK))
return -ENOMEM;
address += PAGE_SIZE;
Patches currently in stable-queue which might be from deller@xxxxxx are
queue-4.9/parisc-use-compat_sys_keyctl.patch
queue-4.9/mm-fix-overflow-check-in-expand_upwards.patch
queue-4.9/parisc-dma-api-return-error-instead-of-bug_on-for-dma-ops-on-non-dma-devs.patch
queue-4.9/parisc-mm-ensure-irqs-are-off-in-switch_mm.patch
queue-4.9/parisc-report-sigsegv-instead-of-sigbus-when-running-out-of-stack.patch