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[Qemu-devel] [PATCH 071/156] block/cloop: validate block_size header fie
From: |
Michael Roth |
Subject: |
[Qemu-devel] [PATCH 071/156] block/cloop: validate block_size header field (CVE-2014-0144) |
Date: |
Tue, 8 Jul 2014 12:17:42 -0500 |
From: Stefan Hajnoczi <address@hidden>
Avoid unbounded s->uncompressed_block memory allocation by checking that
the block_size header field has a reasonable value. Also enforce the
assumption that the value is a non-zero multiple of 512.
These constraints conform to cloop 2.639's code so we accept existing
image files.
Signed-off-by: Stefan Hajnoczi <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
Reviewed-by: Max Reitz <address@hidden>
Signed-off-by: Stefan Hajnoczi <address@hidden>
(cherry picked from commit d65f97a82c4ed48374a764c769d4ba1ea9724e97)
Signed-off-by: Michael Roth <address@hidden>
---
block/cloop.c | 23 +++++++++++++++++++++++
tests/qemu-iotests/075 | 20 ++++++++++++++++++++
tests/qemu-iotests/075.out | 12 ++++++++++++
3 files changed, 55 insertions(+)
diff --git a/block/cloop.c b/block/cloop.c
index b907023..f021663 100644
--- a/block/cloop.c
+++ b/block/cloop.c
@@ -26,6 +26,9 @@
#include "qemu/module.h"
#include <zlib.h>
+/* Maximum compressed block size */
+#define MAX_BLOCK_SIZE (64 * 1024 * 1024)
+
typedef struct BDRVCloopState {
CoMutex lock;
uint32_t block_size;
@@ -68,6 +71,26 @@ static int cloop_open(BlockDriverState *bs, QDict *options,
int flags,
return ret;
}
s->block_size = be32_to_cpu(s->block_size);
+ if (s->block_size % 512) {
+ error_setg(errp, "block_size %u must be a multiple of 512",
+ s->block_size);
+ return -EINVAL;
+ }
+ if (s->block_size == 0) {
+ error_setg(errp, "block_size cannot be zero");
+ return -EINVAL;
+ }
+
+ /* cloop's create_compressed_fs.c warns about block sizes beyond 256 KB but
+ * we can accept more. Prevent ridiculous values like 4 GB - 1 since we
+ * need a buffer this big.
+ */
+ if (s->block_size > MAX_BLOCK_SIZE) {
+ error_setg(errp, "block_size %u must be %u MB or less",
+ s->block_size,
+ MAX_BLOCK_SIZE / (1024 * 1024));
+ return -EINVAL;
+ }
ret = bdrv_pread(bs->file, 128 + 4, &s->n_blocks, 4);
if (ret < 0) {
diff --git a/tests/qemu-iotests/075 b/tests/qemu-iotests/075
index 88ae8bb..8f54a99 100755
--- a/tests/qemu-iotests/075
+++ b/tests/qemu-iotests/075
@@ -42,11 +42,31 @@ _supported_fmt cloop
_supported_proto generic
_supported_os Linux
+block_size_offset=128
+
echo
echo "== check that the first sector can be read =="
_use_sample_img simple-pattern.cloop.bz2
$QEMU_IO -c "read 0 512" $TEST_IMG 2>&1 | _filter_qemu_io | _filter_testdir
+echo
+echo "== block_size must be a multiple of 512 =="
+_use_sample_img simple-pattern.cloop.bz2
+poke_file "$TEST_IMG" "$block_size_offset" "\x00\x00\x02\x01"
+$QEMU_IO -c "read 0 512" $TEST_IMG 2>&1 | _filter_qemu_io | _filter_testdir
+
+echo
+echo "== block_size cannot be zero =="
+_use_sample_img simple-pattern.cloop.bz2
+poke_file "$TEST_IMG" "$block_size_offset" "\x00\x00\x00\x00"
+$QEMU_IO -c "read 0 512" $TEST_IMG 2>&1 | _filter_qemu_io | _filter_testdir
+
+echo
+echo "== huge block_size ==="
+_use_sample_img simple-pattern.cloop.bz2
+poke_file "$TEST_IMG" "$block_size_offset" "\xff\xff\xfe\x00"
+$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/075.out b/tests/qemu-iotests/075.out
index 26661fa..d362c95 100644
--- a/tests/qemu-iotests/075.out
+++ b/tests/qemu-iotests/075.out
@@ -3,4 +3,16 @@ QA output created by 075
== check that the first sector can be read ==
read 512/512 bytes at offset 0
512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== block_size must be a multiple of 512 ==
+qemu-io: can't open device TEST_DIR/simple-pattern.cloop: block_size 513 must
be a multiple of 512
+no file open, try 'help open'
+
+== block_size cannot be zero ==
+qemu-io: can't open device TEST_DIR/simple-pattern.cloop: block_size cannot be
zero
+no file open, try 'help open'
+
+== huge block_size ===
+qemu-io: can't open device TEST_DIR/simple-pattern.cloop: block_size
4294966784 must be 64 MB or less
+no file open, try 'help open'
*** done
--
1.9.1
- [Qemu-devel] [PATCH 096/156] qcow2: Don't rely on free_cluster_index in alloc_refcount_block() (CVE-2014-0147), (continued)
- [Qemu-devel] [PATCH 096/156] qcow2: Don't rely on free_cluster_index in alloc_refcount_block() (CVE-2014-0147), Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 150/156] nbd: Close socket on negotiation failure., Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 148/156] nbd: Don't export a block device with no medium., Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 154/156] sdhci: Fix misuse of qemu_free_irqs(), Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 149/156] nbd: Don't validate from and len in NBD_CMD_DISC., Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 153/156] vnc: Fix tight_detect_smooth_image() for lossless case, Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 144/156] coroutine-win32.c: Add noinline attribute to work around gcc bug, Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 156/156] pci: assign devfn to pci_dev before calling pci_device_iommu_address_space(), Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 080/156] bochs: Check extent_size header field (CVE-2014-0142), Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 106/156] dmg: sanitize chunk length and sectorcount (CVE-2014-0145), Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 071/156] block/cloop: validate block_size header field (CVE-2014-0144),
Michael Roth <=
- [Qemu-devel] [PATCH 019/156] ide: Correct improper smart self test counter reset in ide core., Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 111/156] qcow2: Fix copy_sectors() with VM state, Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 007/156] scsi: Change scsi sense buf size to 252, Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 081/156] bochs: Fix bitmap offset calculation, Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 043/156] Fix vmstate_info_int32_le comparison/assign, Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 014/156] virtio-net: Do not filter VLANs without F_CTRL_VLAN, Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 101/156] qcow2: Fix new L1 table size check (CVE-2014-0143), Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 103/156] dmg: prevent out-of-bounds array access on terminator, Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 082/156] vpc/vhd: add bounds check for max_table_entries and block_size (CVE-2014-0144), Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 152/156] qapi: zero-initialize all QMP command parameters, Michael Roth, 2014/07/08