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| author | Kevin Wolf | 2014-03-26 13:06:04 +0100 |
|---|---|---|
| committer | Stefan Hajnoczi | 2014-04-01 15:22:35 +0200 |
| commit | 11b128f4062dd7f89b14abc8877ff20d41b28be9 (patch) | |
| tree | dbbe66c763e4fd486d13703617ba092e7e7437e6 /block | |
| parent | qcow2: Fix copy_sectors() with VM state (diff) | |
| download | qemu-11b128f4062dd7f89b14abc8877ff20d41b28be9.tar.gz qemu-11b128f4062dd7f89b14abc8877ff20d41b28be9.tar.xz qemu-11b128f4062dd7f89b14abc8877ff20d41b28be9.zip | |
qcow2: Fix NULL dereference in qcow2_open() error path (CVE-2014-0146)
The qcow2 code assumes that s->snapshots is non-NULL if s->nb_snapshots
!= 0. By having the initialisation of both fields separated in
qcow2_open(), any error occuring in between would cause the error path
to dereference NULL in qcow2_free_snapshots() if the image had any
snapshots.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/qcow2.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index b64564d171..be48a27afa 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -637,9 +637,6 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } - s->snapshots_offset = header.snapshots_offset; - s->nb_snapshots = header.nb_snapshots; - /* read the level 1 table */ if (header.l1_size > 0x2000000) { /* 32 MB L1 table is enough for 2 PB images at 64k cluster size @@ -734,6 +731,10 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, bs->backing_file[len] = '\0'; } + /* Internal snapshots */ + s->snapshots_offset = header.snapshots_offset; + s->nb_snapshots = header.nb_snapshots; + ret = qcow2_read_snapshots(bs); if (ret < 0) { error_setg_errno(errp, -ret, "Could not read snapshots"); |