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From b00154f43c01657e4299c486f451ad50891d80f1 Mon Sep 17 00:00:00 2001
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From: Fam Zheng <famz@redhat.com>
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Date: Fri, 29 Jun 2018 06:11:52 +0200
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Subject: [PATCH 178/268] iscsi: Don't blindly use designator length in
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 response for memcpy
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RH-Author: Fam Zheng <famz@redhat.com>
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Message-id: <20180629061153.12687-13-famz@redhat.com>
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Patchwork-id: 81162
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O-Subject: [RHEL-7.6 qemu-kvm-rhev PATCH v2 12/13] iscsi: Don't blindly use designator length in response for memcpy
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Bugzilla: 1482537
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RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
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RH-Acked-by: Max Reitz <mreitz@redhat.com>
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RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
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Per SCSI definition the designator_length we receive from INQUIRY is 8,
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12 or at most 16, but we should be careful because the remote iscsi
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target may misbehave, otherwise we could have a buffer overflow.
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Reported-by: Max Reitz <mreitz@redhat.com>
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Signed-off-by: Fam Zheng <famz@redhat.com>
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Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
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---
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 block/iscsi.c | 2 +-
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 1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/block/iscsi.c b/block/iscsi.c
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index fbcd5bb..751884d 100644
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--- a/block/iscsi.c
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+++ b/block/iscsi.c
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@@ -2226,7 +2226,7 @@ static void iscsi_populate_target_desc(unsigned char *desc, IscsiLun *lun)
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     desc[5] = (dd->designator_type & 0xF)
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         | ((dd->association & 3) << 4);
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     desc[7] = dd->designator_length;
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-    memcpy(desc + 8, dd->designator, dd->designator_length);
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+    memcpy(desc + 8, dd->designator, MIN(dd->designator_length, 20));
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     desc[28] = 0;
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     desc[29] = (lun->block_size >> 16) & 0xFF;
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-- 
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1.8.3.1
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