releases/4.14.111/mm-vmalloc.c-fix-kernel-bug-at-mm-vmalloc.c-512.patch

   1 From 589573fb8ded5e111e86f71bbec495c47039a7a0 Mon Sep 17 00:00:00 2001
   2 From: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
   3 Date: Tue, 5 Mar 2019 15:45:59 -0800
   4 Subject: mm/vmalloc.c: fix kernel BUG at mm/vmalloc.c:512!
   5
   6 [ Upstream commit afd07389d3f4933c7f7817a92fb5e053d59a3182 ]
   7
   8 One of the vmalloc stress test case triggers the kernel BUG():
   9
  10   <snip>
  11   [60.562151] ------------[ cut here ]------------
  12   [60.562154] kernel BUG at mm/vmalloc.c:512!
  13   [60.562206] invalid opcode: 0000 [#1] PREEMPT SMP PTI
  14   [60.562247] CPU: 0 PID: 430 Comm: vmalloc_test/0 Not tainted 4.20.0+ #161
  15   [60.562293] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
  16   [60.562351] RIP: 0010:alloc_vmap_area+0x36f/0x390
  17   <snip>
  18
  19 it can happen due to big align request resulting in overflowing of
  20 calculated address, i.e.  it becomes 0 after ALIGN()'s fixup.
  21
  22 Fix it by checking if calculated address is within vstart/vend range.
  23
  24 Link: http://lkml.kernel.org/r/20190124115648.9433-2-urezki@gmail.com
  25 Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
  26 Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
  27 Cc: Ingo Molnar <mingo@elte.hu>
  28 Cc: Joel Fernandes <joelaf@google.com>
  29 Cc: Matthew Wilcox <willy@infradead.org>
  30 Cc: Michal Hocko <mhocko@suse.com>
  31 Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
  32 Cc: Steven Rostedt <rostedt@goodmis.org>
  33 Cc: Tejun Heo <tj@kernel.org>
  34 Cc: Thomas Garnier <thgarnie@google.com>
  35 Cc: Thomas Gleixner <tglx@linutronix.de>
  36 Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
  37 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
  38 Signed-off-by: Sasha Levin <sashal@kernel.org>
  39 ---
  40  mm/vmalloc.c | 6 +++++-
  41  1 file changed, 5 insertions(+), 1 deletion(-)
  42
  43 diff --git a/mm/vmalloc.c b/mm/vmalloc.c
  44 index 8d9f636d0c98..6c906f6f16cc 100644
  45 --- a/mm/vmalloc.c
  46 +++ b/mm/vmalloc.c
  47 @@ -498,7 +498,11 @@ nocache:
  48         }
  49
  50  found:
  51 -       if (addr + size > vend)
  52 +       /*
  53 +        * Check also calculated address against the vstart,
  54 +        * because it can be 0 because of big align request.
  55 +        */
  56 +       if (addr + size > vend || addr < vstart)
  57                 goto overflow;
  58
  59         va->va_start = addr;
  60 --
  61 2.19.1
  62