70 lines
2.7 KiB
Diff
70 lines
2.7 KiB
Diff
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From 66ad3c6ecce098d8f01545859c5ebf7a9e505e2c Mon Sep 17 00:00:00 2001
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From: Tuguoyi <tu.guoyi@h3c.com>
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Date: Fri, 1 Nov 2019 07:37:35 +0000
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Subject: [PATCH] qcow2-bitmap: Fix uint64_t left-shift overflow
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There are two issues in In check_constraints_on_bitmap(),
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1) The sanity check on the granularity will cause uint64_t
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integer left-shift overflow when cluster_size is 2M and the
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granularity is BIGGER than 32K.
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2) The way to calculate image size that the maximum bitmap
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supported can map to is a bit incorrect.
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This patch fix it by add a helper function to calculate the
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number of bytes needed by a normal bitmap in image and compare
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it to the maximum bitmap bytes supported by qemu.
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Fixes: 5f72826e7fc62167cf3a
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Signed-off-by: Guoyi Tu <tu.guoyi@h3c.com>
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Message-id: 4ba40cd1e7ee4a708b40899952e49f22@h3c.com
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Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
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Cc: qemu-stable@nongnu.org
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Signed-off-by: Max Reitz <mreitz@redhat.com>
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(cherry picked from commit 570542ecb11e04b61ef4b3f4d0965a6915232a88)
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Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
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---
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block/qcow2-bitmap.c | 14 +++++++++++---
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1 file changed, 11 insertions(+), 3 deletions(-)
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diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
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index e53a160..997923f 100644
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--- a/block/qcow2-bitmap.c
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+++ b/block/qcow2-bitmap.c
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@@ -143,6 +143,13 @@ static int check_table_entry(uint64_t entry, int cluster_size)
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return 0;
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}
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+static int64_t get_bitmap_bytes_needed(int64_t len, uint32_t granularity)
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+{
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+ int64_t num_bits = DIV_ROUND_UP(len, granularity);
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+
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+ return DIV_ROUND_UP(num_bits, 8);
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+}
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+
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static int check_constraints_on_bitmap(BlockDriverState *bs,
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const char *name,
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uint32_t granularity,
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@@ -151,6 +158,7 @@ static int check_constraints_on_bitmap(BlockDriverState *bs,
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BDRVQcow2State *s = bs->opaque;
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int granularity_bits = ctz32(granularity);
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int64_t len = bdrv_getlength(bs);
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+ int64_t bitmap_bytes;
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assert(granularity > 0);
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assert((granularity & (granularity - 1)) == 0);
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@@ -172,9 +180,9 @@ static int check_constraints_on_bitmap(BlockDriverState *bs,
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return -EINVAL;
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}
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- if ((len > (uint64_t)BME_MAX_PHYS_SIZE << granularity_bits) ||
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- (len > (uint64_t)BME_MAX_TABLE_SIZE * s->cluster_size <<
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- granularity_bits))
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+ bitmap_bytes = get_bitmap_bytes_needed(len, granularity);
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+ if ((bitmap_bytes > (uint64_t)BME_MAX_PHYS_SIZE) ||
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+ (bitmap_bytes > (uint64_t)BME_MAX_TABLE_SIZE * s->cluster_size))
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{
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error_setg(errp, "Too much space will be occupied by the bitmap. "
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"Use larger granularity");
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--
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1.8.3.1
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