From 068db0239a84597147a62d02cfef5bcf840dbb4c Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 23 Jun 2010 10:48:10 -0300 Subject: [PATCH 05/11] qcow2: Fix qemu-img check segfault on corrupted images RH-Author: Kevin Wolf Message-id: <1277290092-8810-2-git-send-email-kwolf@redhat.com> Patchwork-id: 10105 O-Subject: [RHEL-6 qemu-kvm PATCH 1/3] qcow2: Fix qemu-img check segfault on corrupted images Bugzilla: 604210 RH-Acked-by: Amit Shah RH-Acked-by: Christoph Hellwig RH-Acked-by: Jes Sorensen Bugzilla: 604210 With corrupted images, we can easily get an cluster index that exceeds the array size of the temporary refcount table. Signed-off-by: Kevin Wolf (cherry picked from commit 6882c8fa78dcc4882640d3e11232d995fda7d5c4) --- block/qcow2-refcount.c | 14 +++++++++++--- 1 files changed, 11 insertions(+), 3 deletions(-) Signed-off-by: Eduardo Habkost --- block/qcow2-refcount.c | 14 +++++++++++--- 1 files changed, 11 insertions(+), 3 deletions(-) diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index 4355ceb..4781d53 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -1141,22 +1141,30 @@ int qcow2_check_refcounts(BlockDriverState *bs) s->refcount_table_offset, s->refcount_table_size * sizeof(uint64_t)); for(i = 0; i < s->refcount_table_size; i++) { - int64_t offset; + uint64_t offset, cluster; offset = s->refcount_table[i]; + cluster = offset >> s->cluster_bits; /* Refcount blocks are cluster aligned */ if (offset & (s->cluster_size - 1)) { fprintf(stderr, "ERROR refcount block %d is not " "cluster aligned; refcount table entry corrupted\n", i); errors++; + continue; + } + + if (cluster >= nb_clusters) { + fprintf(stderr, "ERROR refcount block %d is outside image\n", i); + errors++; + continue; } if (offset != 0) { errors += inc_refcounts(bs, refcount_table, nb_clusters, offset, s->cluster_size); - if (refcount_table[offset / s->cluster_size] != 1) { + if (refcount_table[cluster] != 1) { fprintf(stderr, "ERROR refcount block %d refcount=%d\n", - i, refcount_table[offset / s->cluster_size]); + i, refcount_table[cluster]); } } } -- 1.7.0.3