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From 8d0f3218313c74d2e9df015385b809a7cb03734e Mon Sep 17 00:00:00 2001
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From: Kevin Wolf <kwolf@redhat.com>
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Date: Tue, 25 Mar 2014 14:23:55 +0100
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Subject: [PATCH 48/49] parallels: Sanity check for s->tracks (CVE-2014-0142)
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RH-Author: Kevin Wolf <kwolf@redhat.com>
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Message-id: <1395753835-7591-49-git-send-email-kwolf@redhat.com>
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Patchwork-id: n/a
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O-Subject: [virt-devel] [EMBARGOED RHEL-7.0 qemu-kvm PATCH 48/48] parallels: Sanity check for s->tracks (CVE-2014-0142)
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Bugzilla: 1079315
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RH-Acked-by: Jeff Cody <jcody@redhat.com>
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RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
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RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
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Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1079315
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Upstream status: Embargoed
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This avoids a possible division by zero.
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Convert s->tracks to unsigned as well because it feels better than
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surviving just because the results of calculations with s->tracks are
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converted to unsigned anyway.
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Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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---
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 block/parallels.c          |    7 ++++++-
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 tests/qemu-iotests/076     |    7 +++++++
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 tests/qemu-iotests/076.out |    4 ++++
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 3 files changed, 17 insertions(+), 1 deletions(-)
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diff --git a/block/parallels.c b/block/parallels.c
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index 5d1c0af..d83cde4 100644
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--- a/block/parallels.c
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+++ b/block/parallels.c
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@@ -51,7 +51,7 @@ typedef struct BDRVParallelsState {
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     uint32_t *catalog_bitmap;
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     unsigned int catalog_size;
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-    int tracks;
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+    unsigned int tracks;
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 } BDRVParallelsState;
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 static int parallels_probe(const uint8_t *buf, int buf_size, const char *filename)
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@@ -92,6 +92,11 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
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     bs->total_sectors = le32_to_cpu(ph.nb_sectors);
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     s->tracks = le32_to_cpu(ph.tracks);
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+    if (s->tracks == 0) {
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+        error_setg(errp, "Invalid image: Zero sectors per track");
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+        ret = -EINVAL;
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+        goto fail;
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+    }
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     s->catalog_size = le32_to_cpu(ph.catalog_entries);
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     if (s->catalog_size > INT_MAX / 4) {
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diff --git a/tests/qemu-iotests/076 b/tests/qemu-iotests/076
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index 6028ac5..b614a7d 100755
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--- a/tests/qemu-iotests/076
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+++ b/tests/qemu-iotests/076
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@@ -42,6 +42,7 @@ _supported_fmt parallels
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 _supported_proto generic
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 _supported_os Linux
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+tracks_offset=$((0x1c))
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 catalog_entries_offset=$((0x20))
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 nb_sectors_offset=$((0x24))
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@@ -63,6 +64,12 @@ poke_file "$TEST_IMG" "$nb_sectors_offset" "\xff\xff\xff\xff"
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 poke_file "$TEST_IMG" "$catalog_entries_offset" "\x01\x00\x00\x40"
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 { $QEMU_IO -c "read 64M 64M" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
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+echo
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+echo "== Zero sectors per track =="
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+_use_sample_img fake.parallels.bz2
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+poke_file "$TEST_IMG" "$tracks_offset" "\x00\x00\x00\x00"
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+{ $QEMU_IO -c "read 0 512" $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/076.out b/tests/qemu-iotests/076.out
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index 12af42a..f7745d8 100644
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--- a/tests/qemu-iotests/076.out
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+++ b/tests/qemu-iotests/076.out
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@@ -11,4 +11,8 @@ no file open, try 'help open'
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 == Overflow in catalog allocation ==
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 qemu-io: can't open device TEST_DIR/fake.parallels: Catalog too large
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 no file open, try 'help open'
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+
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+== Zero sectors per track ==
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+qemu-io: can't open device TEST_DIR/fake.parallels: Invalid image: Zero sectors per track
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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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