58 lines
1.9 KiB
Diff
58 lines
1.9 KiB
Diff
From 46485de0cb357b57373e1ca895adedf1f3ed46ec Mon Sep 17 00:00:00 2001
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From: Kevin Wolf <kwolf@redhat.com>
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Date: Thu, 8 May 2014 13:08:20 +0200
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Subject: [PATCH] qcow1: Validate image size (CVE-2014-0223)
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A huge image size could cause s->l1_size to overflow. Make sure that
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images never require a L1 table larger than what fits in s->l1_size.
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This cannot only cause unbounded allocations, but also the allocation of
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a too small L1 table, resulting in out-of-bounds array accesses (both
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reads and writes).
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Cc: qemu-stable@nongnu.org
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Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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---
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block/qcow.c | 16 ++++++++++++++--
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tests/qemu-iotests/092 | 9 +++++++++
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tests/qemu-iotests/092.out | 7 +++++++
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3 files changed, 30 insertions(+), 2 deletions(-)
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diff --git a/block/qcow.c b/block/qcow.c
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index e8038e5..3566c05 100644
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--- a/block/qcow.c
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+++ b/block/qcow.c
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@@ -61,7 +61,7 @@ typedef struct BDRVQcowState {
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int cluster_sectors;
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int l2_bits;
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int l2_size;
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- int l1_size;
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+ unsigned int l1_size;
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uint64_t cluster_offset_mask;
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uint64_t l1_table_offset;
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uint64_t *l1_table;
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@@ -166,7 +166,19 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags,
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/* read the level 1 table */
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shift = s->cluster_bits + s->l2_bits;
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- s->l1_size = (header.size + (1LL << shift) - 1) >> shift;
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+ if (header.size > UINT64_MAX - (1LL << shift)) {
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+ error_setg(errp, "Image too large");
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+ ret = -EINVAL;
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+ goto fail;
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+ } else {
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+ uint64_t l1_size = (header.size + (1LL << shift) - 1) >> shift;
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+ if (l1_size > INT_MAX / sizeof(uint64_t)) {
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+ error_setg(errp, "Image too large");
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+ ret = -EINVAL;
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+ goto fail;
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+ }
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+ s->l1_size = l1_size;
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+ }
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s->l1_table_offset = header.l1_table_offset;
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s->l1_table = g_malloc(s->l1_size * sizeof(uint64_t));
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--
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1.9.3
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