Blame SOURCES/kvm-qcow1-Validate-image-size-CVE-2014-0223.patch

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From a193c89099b75ab17e530fb909813373f72c1ca7 Mon Sep 17 00:00:00 2001
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From: Kevin Wolf <kwolf@redhat.com>
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Date: Mon, 2 Jun 2014 13:54:47 +0200
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Subject: [PATCH 26/30] qcow1: Validate image size (CVE-2014-0223)
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RH-Author: Kevin Wolf <kwolf@redhat.com>
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Message-id: <1401717288-3918-6-git-send-email-kwolf@redhat.com>
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Patchwork-id: 59101
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O-Subject: [RHEL-7.1/7.0.z qemu-kvm PATCH 5/6] qcow1: Validate image size (CVE-2014-0223)
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Bugzilla: 1097236
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RH-Acked-by: Max Reitz <mreitz@redhat.com>
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RH-Acked-by: Fam Zheng <famz@redhat.com>
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RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
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RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
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A huge image size could cause s->l1_size to overflow. Make sure that
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images never require a L1 table larger than what fits in s->l1_size.
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This cannot only cause unbounded allocations, but also the allocation of
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a too small L1 table, resulting in out-of-bounds array accesses (both
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reads and writes).
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Cc: qemu-stable@nongnu.org
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Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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(cherry picked from commit 46485de0cb357b57373e1ca895adedf1f3ed46ec)
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---
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 block/qcow.c               | 16 ++++++++++++++--
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 tests/qemu-iotests/092     |  9 +++++++++
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 tests/qemu-iotests/092.out |  7 +++++++
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 3 files changed, 30 insertions(+), 2 deletions(-)
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Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
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---
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 block/qcow.c               |   16 ++++++++++++++--
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 tests/qemu-iotests/092     |    9 +++++++++
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 tests/qemu-iotests/092.out |    7 +++++++
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 3 files changed, 30 insertions(+), 2 deletions(-)
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diff --git a/block/qcow.c b/block/qcow.c
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index f266701..4fdc751 100644
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--- a/block/qcow.c
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+++ b/block/qcow.c
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@@ -61,7 +61,7 @@ typedef struct BDRVQcowState {
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     int cluster_sectors;
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     int l2_bits;
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     int l2_size;
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-    int l1_size;
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+    unsigned int l1_size;
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     uint64_t cluster_offset_mask;
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     uint64_t l1_table_offset;
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     uint64_t *l1_table;
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@@ -164,7 +164,19 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags,
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     /* read the level 1 table */
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     shift = s->cluster_bits + s->l2_bits;
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-    s->l1_size = (header.size + (1LL << shift) - 1) >> shift;
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+    if (header.size > UINT64_MAX - (1LL << shift)) {
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+        error_setg(errp, "Image too large");
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+        ret = -EINVAL;
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+        goto fail;
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+    } else {
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+        uint64_t l1_size = (header.size + (1LL << shift) - 1) >> shift;
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+        if (l1_size > INT_MAX / sizeof(uint64_t)) {
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+            error_setg(errp, "Image too large");
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+            ret = -EINVAL;
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+            goto fail;
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+        }
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+        s->l1_size = l1_size;
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+    }
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     s->l1_table_offset = header.l1_table_offset;
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     s->l1_table = g_malloc(s->l1_size * sizeof(uint64_t));
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diff --git a/tests/qemu-iotests/092 b/tests/qemu-iotests/092
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index fb8bacc..ae6ca76 100755
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--- a/tests/qemu-iotests/092
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+++ b/tests/qemu-iotests/092
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@@ -43,6 +43,7 @@ _supported_fmt qcow
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 _supported_proto generic
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 _supported_os Linux
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+offset_size=24
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 offset_cluster_bits=32
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 offset_l2_bits=33
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@@ -72,6 +73,14 @@ poke_file "$TEST_IMG" "$offset_l2_bits" "\x0e"
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 poke_file "$TEST_IMG" "$offset_l2_bits" "\x1b"
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 { $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
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+echo
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+echo "== Invalid size =="
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+_make_test_img 64M
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+poke_file "$TEST_IMG" "$offset_size" "\xee\xee\xee\xee\xee\xee\xee\xee"
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+{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
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+poke_file "$TEST_IMG" "$offset_size" "\x7f\xff\xff\xff\xff\xff\xff\xff"
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+{ $QEMU_IO -c "write 0 64M" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
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+
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 # success, all done
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 echo "*** done"
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 rm -f $seq.full
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diff --git a/tests/qemu-iotests/092.out b/tests/qemu-iotests/092.out
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index 73918b3..ac03302 100644
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--- a/tests/qemu-iotests/092.out
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+++ b/tests/qemu-iotests/092.out
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@@ -21,4 +21,11 @@ qemu-io: can't open device TEST_DIR/t.qcow: L2 table size must be between 512 an
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 no file open, try 'help open'
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 qemu-io: can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k
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 no file open, try 'help open'
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+
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+== Invalid size ==
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+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 
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+qemu-io: can't open device TEST_DIR/t.qcow: Image too large
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+no file open, try 'help open'
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+qemu-io: can't open device TEST_DIR/t.qcow: Image too large
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+no file open, try 'help open'
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 *** done
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-- 
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1.7.1
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