This is a note to let you know that I've just added the patch titled

    mm/vmalloc.c: fix an overflow bug in alloc_vmap_area()

to the 3.10-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-vmalloc.c-fix-an-overflow-bug-in-alloc_vmap_area.patch
and it can be found in the queue-3.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From bcb615a81b1765864c71c50afb56631e7a1e5283 Mon Sep 17 00:00:00 2001
From: Zhang Yanfei <[email protected]>
Date: Mon, 8 Jul 2013 16:00:19 -0700
Subject: mm/vmalloc.c: fix an overflow bug in alloc_vmap_area()

From: Zhang Yanfei <[email protected]>

commit bcb615a81b1765864c71c50afb56631e7a1e5283 upstream.

When searching a vmap area in the vmalloc space, we use (addr + size -
1) to check if the value is less than addr, which is an overflow.  But
we assign (addr + size) to vmap_area->va_end.

So if we come across the below case:

  (addr + size - 1) : not overflow
  (addr + size)     : overflow

we will assign an overflow value (e.g 0) to vmap_area->va_end, And this
will trigger BUG in __insert_vmap_area, causing system panic.

So using (addr + size) to check the overflow should be the correct
behaviour, not (addr + size - 1).

Signed-off-by: Zhang Yanfei <[email protected]>
Reported-by: Ghennadi Procopciuc <[email protected]>
Tested-by: Daniel Baluta <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: KOSAKI Motohiro <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Cc: Anatoly Muliarski <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 mm/vmalloc.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -388,12 +388,12 @@ nocache:
                addr = ALIGN(first->va_end, align);
                if (addr < vstart)
                        goto nocache;
-               if (addr + size - 1 < addr)
+               if (addr + size < addr)
                        goto overflow;
 
        } else {
                addr = ALIGN(vstart, align);
-               if (addr + size - 1 < addr)
+               if (addr + size < addr)
                        goto overflow;
 
                n = vmap_area_root.rb_node;
@@ -420,7 +420,7 @@ nocache:
                if (addr + cached_hole_size < first->va_start)
                        cached_hole_size = first->va_start - addr;
                addr = ALIGN(first->va_end, align);
-               if (addr + size - 1 < addr)
+               if (addr + size < addr)
                        goto overflow;
 
                if (list_is_last(&first->list, &vmap_area_list))


Patches currently in stable-queue which might be from [email protected] 
are

queue-3.10/mm-vmalloc.c-fix-an-overflow-bug-in-alloc_vmap_area.patch
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