From 246f65838d19db6db55bfb41117c35645a2c4789 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 26 Mar 2014 13:05:32 +0100 Subject: [PATCH] bochs: Use unsigned variables for offsets and sizes (CVE-2014-0147) Gets us rid of integer overflows resulting in negative sizes which aren't correctly checked. Signed-off-by: Kevin Wolf Reviewed-by: Stefan Hajnoczi Reviewed-by: Max Reitz Signed-off-by: Stefan Hajnoczi --- block/bochs.c | 16 ++++++++-------- tests/qemu-iotests/078 | 8 ++++++++ tests/qemu-iotests/078.out | 4 ++++ 3 files changed, 20 insertions(+), 8 deletions(-) diff --git a/block/bochs.c b/block/bochs.c index ef8e381ba0..e923eedf3e 100644 --- a/block/bochs.c +++ b/block/bochs.c @@ -67,13 +67,13 @@ struct bochs_header { typedef struct BDRVBochsState { CoMutex lock; uint32_t *catalog_bitmap; - int catalog_size; + uint32_t catalog_size; - int data_offset; + uint32_t data_offset; - int bitmap_blocks; - int extent_blocks; - int extent_size; + uint32_t bitmap_blocks; + uint32_t extent_blocks; + uint32_t extent_size; } BDRVBochsState; static int bochs_probe(const uint8_t *buf, int buf_size, const char *filename) @@ -97,7 +97,7 @@ static int bochs_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { BDRVBochsState *s = bs->opaque; - int i; + uint32_t i; struct bochs_header bochs; int ret; @@ -153,8 +153,8 @@ fail: static int64_t seek_to_sector(BlockDriverState *bs, int64_t sector_num) { BDRVBochsState *s = bs->opaque; - int64_t offset = sector_num * 512; - int64_t extent_index, extent_offset, bitmap_offset; + uint64_t offset = sector_num * 512; + uint64_t extent_index, extent_offset, bitmap_offset; char bitmap_entry; // seek to sector diff --git a/tests/qemu-iotests/078 b/tests/qemu-iotests/078 index f55f46d92b..73b573a624 100755 --- a/tests/qemu-iotests/078 +++ b/tests/qemu-iotests/078 @@ -42,11 +42,19 @@ _supported_fmt bochs _supported_proto generic _supported_os Linux +catalog_size_offset=$((0x48)) + echo echo "== Read from a valid image ==" _use_sample_img empty.bochs.bz2 { $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir +echo +echo "== Negative catalog size ==" +_use_sample_img empty.bochs.bz2 +poke_file "$TEST_IMG" "$catalog_size_offset" "\xff\xff\xff\xff" +{ $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 25d37c5dcd..ef8c42de9c 100644 --- a/tests/qemu-iotests/078.out +++ b/tests/qemu-iotests/078.out @@ -3,4 +3,8 @@ QA output created by 078 == Read from a valid image == read 512/512 bytes at offset 0 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) + +== Negative catalog size == +qemu-io: can't open device TEST_DIR/empty.bochs: Could not open 'TEST_DIR/empty.bochs': Interrupted system call +no file open, try 'help open' *** done -- GitLab