This is a note to let you know that I've just added the patch titled
drm/radeon: forbid mapping of userptr bo through radeon device file
to the 4.5-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:
drm-radeon-forbid-mapping-of-userptr-bo-through-radeon-device-file.patch
and it can be found in the queue-4.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b5dcec693f87cb8475f2291c0075b2422addd3d6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= <jglisse@xxxxxxxxxx>
Date: Tue, 19 Apr 2016 09:07:50 -0400
Subject: drm/radeon: forbid mapping of userptr bo through radeon device file
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From: Jérôme Glisse <jglisse@xxxxxxxxxx>
commit b5dcec693f87cb8475f2291c0075b2422addd3d6 upstream.
Allowing userptr bo which are basicly a list of page from some vma
(so either anonymous page or file backed page) would lead to serious
corruption of kernel structures and counters (because we overwrite
the page->mapping field when mapping buffer).
This will already block if the buffer was populated before anyone does
try to mmap it because then TTM_PAGE_FLAG_SG would be set in in the
ttm_tt flags. But that flag is check before ttm_tt_populate in the ttm
vm fault handler.
So to be safe just add a check to verify_access() callback.
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
Signed-off-by: Jérôme Glisse <jglisse@xxxxxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/radeon/radeon_ttm.c | 2 ++
1 file changed, 2 insertions(+)
--- a/drivers/gpu/drm/radeon/radeon_ttm.c
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c
@@ -235,6 +235,8 @@ static int radeon_verify_access(struct t
{
struct radeon_bo *rbo = container_of(bo, struct radeon_bo, tbo);
+ if (radeon_ttm_tt_has_userptr(bo->ttm))
+ return -EPERM;
return drm_vma_node_verify_access(&rbo->gem_base.vma_node, filp);
}
Patches currently in stable-queue which might be from jglisse@xxxxxxxxxx are
queue-4.5/drm-radeon-forbid-mapping-of-userptr-bo-through-radeon-device-file.patch
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