Patch "x86/mm/32: Set the '__vmalloc_start_set' flag in initmem_init()" has been added to the 4.9-stable tree

Patch "x86/mm/32: Set the '__vmalloc_start_set' flag in initmem_init()" has been added to the 4.9-stable tree

[gregkh]

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

    x86/mm/32: Set the '__vmalloc_start_set' flag in initmem_init()

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:
     x86-mm-32-set-the-__vmalloc_start_set-flag-in-initmem_init.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@vger.kernel.org> know about it.


>From 861ce4a3244c21b0af64f880d5bfe5e6e2fb9e4a Mon Sep 17 00:00:00 2001
From: Laura Abbott <labbott@redhat.com>
Date: Mon, 8 May 2017 14:23:16 -0700
Subject: x86/mm/32: Set the '__vmalloc_start_set' flag in initmem_init()

From: Laura Abbott <labbott@redhat.com>

commit 861ce4a3244c21b0af64f880d5bfe5e6e2fb9e4a upstream.

'__vmalloc_start_set' currently only gets set in initmem_init() when
!CONFIG_NEED_MULTIPLE_NODES. This breaks detection of vmalloc address
with virt_addr_valid() with CONFIG_NEED_MULTIPLE_NODES=y, causing
a kernel crash:

  [mm/usercopy] 517e1fbeb6: kernel BUG at arch/x86/mm/physaddr.c:78!

Set '__vmalloc_start_set' appropriately for that case as well.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: dc16ecf7fd1f ("x86-32: use specific __vmalloc_start_set flag in __virt_addr_valid")
Link: http://lkml.kernel.org/r/1494278596-30373-1-git-send-email-labbott@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/mm/numa_32.c |    1 +
 1 file changed, 1 insertion(+)

--- a/arch/x86/mm/numa_32.c
+++ b/arch/x86/mm/numa_32.c
@@ -100,5 +100,6 @@ void __init initmem_init(void)
 	printk(KERN_DEBUG "High memory starts at vaddr %08lx\n",
 			(ulong) pfn_to_kaddr(highstart_pfn));
 
+	__vmalloc_start_set = true;
 	setup_bootmem_allocator();
 }


Patches currently in stable-queue which might be from labbott@redhat.com are

queue-4.9/x86-mm-32-set-the-__vmalloc_start_set-flag-in-initmem_init.patch