5.6-stable patches

added patches:
	usercopy-mark-dma-kmalloc-caches-as-usercopy-caches.patch

diff --git a/queue-5.6/series b/queue-5.6/series
index 324b82b07bd83f7312a6d2fff5460ab3f254bfd5..9e3573771f2070cbcfeae80d2749d5a691fe42da 100644 (file)
--- a/queue-5.6/series
+++ b/queue-5.6/series
@@ -44,3 +44,4 @@ scsi-target-fix-hang-when-multiple-threads-try-to-de.patch
 drm-amd-display-remove-invalid-dc_is_hw_initialized-.patch
 drm-amd-display-not-doing-optimize-bandwidth-if-flip.patch
 aio-fix-async-fsync-creds.patch
+usercopy-mark-dma-kmalloc-caches-as-usercopy-caches.patch

diff --git a/queue-5.6/usercopy-mark-dma-kmalloc-caches-as-usercopy-caches.patch b/queue-5.6/usercopy-mark-dma-kmalloc-caches-as-usercopy-caches.patch
new file mode 100644 (file)
index 0000000..4d27dbc
--- /dev/null
+++ b/queue-5.6/usercopy-mark-dma-kmalloc-caches-as-usercopy-caches.patch
@@ -0,0 +1,82 @@
+From 49f2d2419d60a103752e5fbaf158cf8d07c0d884 Mon Sep 17 00:00:00 2001
+From: Vlastimil Babka <vbabka@suse.cz>
+Date: Mon, 1 Jun 2020 21:45:43 -0700
+Subject: usercopy: mark dma-kmalloc caches as usercopy caches
+
+From: Vlastimil Babka <vbabka@suse.cz>
+
+commit 49f2d2419d60a103752e5fbaf158cf8d07c0d884 upstream.
+
+We have seen a "usercopy: Kernel memory overwrite attempt detected to
+SLUB object 'dma-kmalloc-1 k' (offset 0, size 11)!" error on s390x, as
+IUCV uses kmalloc() with __GFP_DMA because of memory address
+restrictions.  The issue has been discussed [2] and it has been noted
+that if all the kmalloc caches are marked as usercopy, there's little
+reason not to mark dma-kmalloc caches too.  The 'dma' part merely means
+that __GFP_DMA is used to restrict memory address range.
+
+As Jann Horn put it [3]:
+ "I think dma-kmalloc slabs should be handled the same way as normal
+  kmalloc slabs. When a dma-kmalloc allocation is freshly created, it is
+  just normal kernel memory - even if it might later be used for DMA -,
+  and it should be perfectly fine to copy_from_user() into such
+  allocations at that point, and to copy_to_user() out of them at the
+  end. If you look at the places where such allocations are created, you
+  can see things like kmemdup(), memcpy() and so on - all normal
+  operations that shouldn't conceptually be different from usercopy in
+  any relevant way."
+
+Thus this patch marks the dma-kmalloc-* caches as usercopy.
+
+[1] https://bugzilla.suse.com/show_bug.cgi?id=1156053
+[2] https://lore.kernel.org/kernel-hardening/bfca96db-bbd0-d958-7732-76e36c667c68@suse.cz/
+[3] https://lore.kernel.org/kernel-hardening/CAG48ez1a4waGk9kB0WLaSbs4muSoK0AYAVk8=XYaKj4_+6e6Hg@mail.gmail.com/
+
+Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
+Acked-by: Jiri Slaby <jslaby@suse.cz>
+Cc: Jann Horn <jannh@google.com>
+Cc: Christoph Hellwig <hch@infradead.org>
+Cc: Christopher Lameter <cl@linux.com>
+Cc: Julian Wiedmann <jwi@linux.ibm.com>
+Cc: Ursula Braun <ubraun@linux.ibm.com>
+Cc: Alexander Viro <viro@zeniv.linux.org.uk>
+Cc: David Windsor <dave@nullcore.net>
+Cc: Pekka Enberg <penberg@kernel.org>
+Cc: David Rientjes <rientjes@google.com>
+Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
+Cc: Andy Lutomirski <luto@kernel.org>
+Cc: "David S. Miller" <davem@davemloft.net>
+Cc: Laura Abbott <labbott@redhat.com>
+Cc: Mark Rutland <mark.rutland@arm.com>
+Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
+Cc: Paolo Bonzini <pbonzini@redhat.com>
+Cc: Christoffer Dall <christoffer.dall@linaro.org>
+Cc: Dave Kleikamp <dave.kleikamp@oracle.com>
+Cc: Jan Kara <jack@suse.cz>
+Cc: Luis de Bethencourt <luisbg@kernel.org>
+Cc: Marc Zyngier <marc.zyngier@arm.com>
+Cc: Rik van Riel <riel@surriel.com>
+Cc: Matthew Garrett <mjg59@google.com>
+Cc: Michal Kubecek <mkubecek@suse.cz>
+Link: http://lkml.kernel.org/r/7d810f6d-8085-ea2f-7805-47ba3842dc50@suse.cz
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ mm/slab_common.c |    3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+--- a/mm/slab_common.c
++++ b/mm/slab_common.c
+@@ -1303,7 +1303,8 @@ void __init create_kmalloc_caches(slab_f
+                       kmalloc_caches[KMALLOC_DMA][i] = create_kmalloc_cache(
+                               kmalloc_info[i].name[KMALLOC_DMA],
+                               kmalloc_info[i].size,
+-                              SLAB_CACHE_DMA | flags, 0, 0);
++                              SLAB_CACHE_DMA | flags, 0,
++                              kmalloc_info[i].size);
+               }
+       }
+ #endif