| From 3150a448434da70b69e0b96d71223161a78d536f Mon Sep 17 00:00:00 2001 |
| From: Kevin Wolf <kwolf@redhat.com> |
| Date: Tue, 25 Mar 2014 14:23:20 +0100 |
| Subject: [PATCH 13/49] bochs: Check extent_size header field (CVE-2014-0142) |
| |
| RH-Author: Kevin Wolf <kwolf@redhat.com> |
| Message-id: <1395753835-7591-14-git-send-email-kwolf@redhat.com> |
| Patchwork-id: n/a |
| O-Subject: [virt-devel] [EMBARGOED RHEL-7.0 qemu-kvm PATCH 13/48] bochs: Check extent_size header field (CVE-2014-0142) |
| Bugzilla: 1079315 |
| RH-Acked-by: Jeff Cody <jcody@redhat.com> |
| RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com> |
| RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com> |
| |
| Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1079315 |
| Upstream status: Embargoed |
| |
| This fixes two possible division by zero crashes: In bochs_open() and in |
| seek_to_sector(). |
| |
| Signed-off-by: Kevin Wolf <kwolf@redhat.com> |
| Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> |
| |
| block/bochs.c | 8 ++++++++ |
| tests/qemu-iotests/078 | 13 +++++++++++++ |
| tests/qemu-iotests/078.out | 8 ++++++++ |
| 3 files changed, 29 insertions(+), 0 deletions(-) |
| |
| diff --git a/block/bochs.c b/block/bochs.c |
| index d1b1a2c..0ec980a 100644 |
| |
| |
| @@ -147,6 +147,14 @@ static int bochs_open(BlockDriverState *bs, QDict *options, int flags, |
| s->extent_blocks = 1 + (le32_to_cpu(bochs.extent) - 1) / 512; |
| |
| s->extent_size = le32_to_cpu(bochs.extent); |
| + if (s->extent_size == 0) { |
| + error_setg(errp, "Extent size may not be zero"); |
| + return -EINVAL; |
| + } else if (s->extent_size > 0x800000) { |
| + error_setg(errp, "Extent size %" PRIu32 " is too large", |
| + s->extent_size); |
| + return -EINVAL; |
| + } |
| |
| if (s->catalog_size < bs->total_sectors / s->extent_size) { |
| error_setg(errp, "Catalog size is too small for this disk size"); |
| diff --git a/tests/qemu-iotests/078 b/tests/qemu-iotests/078 |
| index 902ef0f..872e734 100755 |
| |
| |
| @@ -43,6 +43,7 @@ _supported_proto generic |
| _supported_os Linux |
| |
| catalog_size_offset=$((0x48)) |
| +extent_size_offset=$((0x50)) |
| disk_size_offset=$((0x58)) |
| |
| echo |
| @@ -68,6 +69,18 @@ _use_sample_img empty.bochs.bz2 |
| poke_file "$TEST_IMG" "$disk_size_offset" "\x00\xc0\x0f\x00\x00\x00\x00\x7f" |
| { $QEMU_IO -c "read 2T 4k" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir |
| |
| +echo |
| +echo "== Negative extent size ==" |
| +_use_sample_img empty.bochs.bz2 |
| +poke_file "$TEST_IMG" "$extent_size_offset" "\xff\xff\xff\xff" |
| +{ $QEMU_IO -c "read 768k 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir |
| + |
| +echo |
| +echo "== Zero extent size ==" |
| +_use_sample_img empty.bochs.bz2 |
| +poke_file "$TEST_IMG" "$extent_size_offset" "\x00\x00\x00\x00" |
| +{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir |
| + |
| # success, all done |
| echo "*** done" |
| rm -f $seq.full |
| diff --git a/tests/qemu-iotests/078.out b/tests/qemu-iotests/078.out |
| index 7254693..ea95ffd 100644 |
| |
| |
| @@ -15,4 +15,12 @@ no file open, try 'help open' |
| == Too small catalog bitmap for image size == |
| qemu-io: can't open device TEST_DIR/empty.bochs: Catalog size is too small for this disk size |
| no file open, try 'help open' |
| + |
| +== Negative extent size == |
| +qemu-io: can't open device TEST_DIR/empty.bochs: Extent size 4294967295 is too large |
| +no file open, try 'help open' |
| + |
| +== Zero extent size == |
| +qemu-io: can't open device TEST_DIR/empty.bochs: Extent size may not be zero |
| +no file open, try 'help open' |
| *** done |
| -- |
| 1.7.1 |
| |