From: <gregkh@linuxfoundation.org>
To: schwidefsky@de.ibm.com, gregkh@linuxfoundation.org
Cc: <stable@vger.kernel.org>, <stable-commits@vger.kernel.org>
Subject: Patch "s390/mm: fix BUG_ON in crst_table_upgrade" has been added to the 4.12-stable tree
Date: Thu, 07 Sep 2017 16:47:56 +0200 [thread overview]
Message-ID: <150479567680221@kroah.com> (raw)
This is a note to let you know that I've just added the patch titled
s390/mm: fix BUG_ON in crst_table_upgrade
to the 4.12-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:
s390-mm-fix-bug_on-in-crst_table_upgrade.patch
and it can be found in the queue-4.12 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 8ab867cb0806a8e195de161fd8883a0578d1d050 Mon Sep 17 00:00:00 2001
From: Martin Schwidefsky <schwidefsky@de.ibm.com>
Date: Thu, 31 Aug 2017 13:18:22 +0200
Subject: s390/mm: fix BUG_ON in crst_table_upgrade
From: Martin Schwidefsky <schwidefsky@de.ibm.com>
commit 8ab867cb0806a8e195de161fd8883a0578d1d050 upstream.
A 31-bit compat process can force a BUG_ON in crst_table_upgrade
with specific, invalid mmap calls, e.g.
mmap((void*) 0x7fff8000, 0x10000, 3, 32, -1, 0)
The arch_get_unmapped_area[_topdown] functions miss an if condition
in the decision to do a page table upgrade.
[ms: Backport to 4.12, minor context change]
Fixes: 9b11c7912d00 ("s390/mm: simplify arch_get_unmapped_area[_topdown]")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/s390/mm/mmap.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/arch/s390/mm/mmap.c
+++ b/arch/s390/mm/mmap.c
@@ -119,7 +119,8 @@ arch_get_unmapped_area(struct file *filp
return addr;
check_asce_limit:
- if (addr + len > current->mm->context.asce_limit) {
+ if (addr + len > current->mm->context.asce_limit &&
+ addr + len <= TASK_SIZE) {
rc = crst_table_upgrade(mm);
if (rc)
return (unsigned long) rc;
@@ -183,7 +184,8 @@ arch_get_unmapped_area_topdown(struct fi
}
check_asce_limit:
- if (addr + len > current->mm->context.asce_limit) {
+ if (addr + len > current->mm->context.asce_limit &&
+ addr + len <= TASK_SIZE) {
rc = crst_table_upgrade(mm);
if (rc)
return (unsigned long) rc;
Patches currently in stable-queue which might be from schwidefsky@de.ibm.com are
queue-4.12/s390-mm-avoid-empty-zero-pages-for-kvm-guests-to-avoid-postcopy-hangs.patch
queue-4.12/s390-mm-fix-bug_on-in-crst_table_upgrade.patch
reply other threads:[~2017-09-07 14:48 UTC|newest]
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