51 lines
1.9 KiB
Diff
51 lines
1.9 KiB
Diff
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From 9399660f4ef94129f4f8ba9277a316bd6e7151b5 Mon Sep 17 00:00:00 2001
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From: Amjad Alsharafi <amjadsharafi10@gmail.com>
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Date: Sat, 20 Jul 2024 18:13:33 +0800
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Subject: [PATCH] vvfat: Fix reading files with non-continuous clusters
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When reading with `read_cluster` we get the `mapping` with
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`find_mapping_for_cluster` and then we call `open_file` for this
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mapping.
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The issue appear when its the same file, but a second cluster that is
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not immediately after it, imagine clusters `500 -> 503`, this will give
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us 2 mappings one has the range `500..501` and another `503..504`, both
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point to the same file, but different offsets.
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When we don't open the file since the path is the same, we won't assign
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`s->current_mapping` and thus accessing way out of bound of the file.
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From our example above, after `open_file` (that didn't open anything) we
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will get the offset into the file with
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`s->cluster_size*(cluster_num-s->current_mapping->begin)`, which will
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give us `0x2000 * (504-500)`, which is out of bound for this mapping and
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will produce some issues.
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Signed-off-by: Amjad Alsharafi <amjadsharafi10@gmail.com>
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Message-ID: <1f3ea115779abab62ba32c788073cdc99f9ad5dd.1721470238.git.amjadsharafi10@gmail.com>
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[kwolf: Simplified the patch based on Amjad's analysis and input]
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Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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(cherry picked from commit 5eed3db336506b529b927ba221fe0d836e5b8819)
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Signed-off-by: zhujun2 <zhujun2_yewu@cmss.chinamobile.com>
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---
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block/vvfat.c | 3 ++-
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1 file changed, 2 insertions(+), 1 deletion(-)
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diff --git a/block/vvfat.c b/block/vvfat.c
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index 5dacc6cfac..9af817088f 100644
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--- a/block/vvfat.c
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+++ b/block/vvfat.c
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@@ -1368,8 +1368,9 @@ static int open_file(BDRVVVFATState* s,mapping_t* mapping)
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return -1;
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vvfat_close_current_file(s);
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s->current_fd = fd;
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- s->current_mapping = mapping;
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}
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+
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+ s->current_mapping = mapping;
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return 0;
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}
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--
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2.41.0.windows.1
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