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authorHu Tao <hutao@cn.fujitsu.com>2014-01-26 11:12:38 +0800
committerKevin Wolf <kwolf@redhat.com>2014-02-09 09:12:39 +0100
commit33304ec9fa484e765c6249673e09e1b7d49c5b85 (patch)
tree9e469f03b22e55233921b39cb9c6ec765dceb293 /block/qcow2.c
parent16f0587e0a5da5b1ad76cb7c3739491bc042201c (diff)
qcow2: fix offset overflow in qcow2_alloc_clusters_at()
When cluster size is big enough it can lead to an offset overflow in qcow2_alloc_clusters_at(). This patch fixes it. The allocation is stopped each time at L2 table boundary (see handle_alloc()), so the possible maximum bytes could be 2^(cluster_bits - 3 + cluster_bits) cluster_bits - 3 is used to compute the number of entry by L2 and the additional cluster_bits is to take into account each clusters referenced by the L2 entries. so int is safe for cluster_bits<=17, unsafe otherwise. Signed-off-by: Hu Tao <hutao@cn.fujitsu.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block/qcow2.c')
0 files changed, 0 insertions, 0 deletions