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Blame SOURCES/kvm-virtio-blk-Treat-read-write-beyond-end-as-invalid.patch

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From 55767ddb818ef53eee50777bd276cbf7e7813bfb Mon Sep 17 00:00:00 2001
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From: Markus Armbruster <armbru@redhat.com>
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Date: Fri, 31 Oct 2014 16:29:54 +0100
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Subject: [PATCH 17/19] virtio-blk: Treat read/write beyond end as invalid
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Message-id: <1414772996-17272-4-git-send-email-armbru@redhat.com>
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Patchwork-id: 62019
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O-Subject: [PATCH RHEL-7.1 qemu-kvm 3/5] virtio-blk: Treat read/write beyond end as invalid
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Bugzilla: 1085232
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RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
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RH-Acked-by: Fam Zheng <famz@redhat.com>
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The block layer fails such reads and writes just fine.  However, they
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then get treated like valid operations that fail: the error action
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gets executed.  Unwanted; reporting the error to the guest is the only
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sensible action.
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Reject them before passing them to the block layer.  This bypasses the
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error action and I/O accounting.
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Signed-off-by: Markus Armbruster <armbru@redhat.com>
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Reviewed-by: Fam Zheng <famz@redhat.com>
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Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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(cherry picked from commit 3c2daac0b98952a858277878cb11294256b39e43)
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Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
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---
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 hw/block/virtio-blk.c | 7 +++++++
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 1 file changed, 7 insertions(+)
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diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
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index ffb311c..4f6aa22 100644
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--- a/hw/block/virtio-blk.c
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+++ b/hw/block/virtio-blk.c
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@@ -284,12 +284,19 @@ static void virtio_blk_handle_flush(VirtIOBlockReq *req, MultiReqBuffer *mrb)
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 static bool virtio_blk_sect_range_ok(VirtIOBlock *dev,
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                                      uint64_t sector, size_t size)
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 {
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+    uint64_t nb_sectors = size >> BDRV_SECTOR_BITS;
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+    uint64_t total_sectors;
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+
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     if (sector & dev->sector_mask) {
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         return false;
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     }
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     if (size % dev->conf->logical_block_size) {
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         return false;
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     }
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+    bdrv_get_geometry(dev->bs, &total_sectors);
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+    if (sector > total_sectors || nb_sectors > total_sectors - sector) {
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+        return false;
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+    }
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     return true;
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 }
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-- 
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1.8.3.1
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