diff options
| author | Helge Deller <deller@gmx.de> | 2017-07-14 14:49:38 -0700 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2017-11-02 10:45:42 +0100 |
| commit | b569326cedfc6e0f2dc1c3cc237ad717e4a5b0f4 (patch) | |
| tree | 151d45569a74ff5c3e3ff62f2d57a562d6163371 | |
| parent | 9efa3d527965d5d6772332841923df8d62810bfe (diff) | |
mm: fix overflow check in expand_upwards()
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@p100.box
Fixes: bd726c90b6b8 ("Allow stack to grow up to address space limit")
Signed-off-by: Helge Deller <deller@gmx.de>
Reported-by: Jörn Engel <joern@purestorage.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
| -rw-r--r-- | mm/mmap.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 3c4e4d7ae54e..d042e254a163 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2132,7 +2132,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) /* 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; |