diff options
| author | Kees Cook <keescook@chromium.org> | 2016-08-02 14:04:54 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-08-02 19:35:15 -0400 |
| commit | ba093a6d9397da8eafcfbaa7d95bd34255da39a0 (patch) | |
| tree | 0c949c629283ee48079fa8ee7f545d90dfb7cab3 /mm/mmap.c | |
| parent | 0036d1f7eb95bcc52977f15507f00dd07018e7e2 (diff) | |
| download | lwn-ba093a6d9397da8eafcfbaa7d95bd34255da39a0.tar.gz lwn-ba093a6d9397da8eafcfbaa7d95bd34255da39a0.zip | |
mm: refuse wrapped vm_brk requests
The vm_brk() alignment calculations should refuse to overflow. The ELF
loader depending on this, but it has been fixed now. No other unsafe
callers have been found.
Link: http://lkml.kernel.org/r/1468014494-25291-3-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Hector Marco-Gisbert <hecmargi@upv.es>
Cc: Ismael Ripoll Ripoll <iripoll@upv.es>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Chen Gang <gang.chen.5i5j@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index d44bee96a5fe..ca9d91bca0d6 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2653,16 +2653,18 @@ static inline void verify_mm_writelocked(struct mm_struct *mm) * anonymous maps. eventually we may be able to do some * brk-specific accounting here. */ -static int do_brk(unsigned long addr, unsigned long len) +static int do_brk(unsigned long addr, unsigned long request) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma, *prev; - unsigned long flags; + unsigned long flags, len; struct rb_node **rb_link, *rb_parent; pgoff_t pgoff = addr >> PAGE_SHIFT; int error; - len = PAGE_ALIGN(len); + len = PAGE_ALIGN(request); + if (len < request) + return -ENOMEM; if (!len) return 0; |