From: "Yan, Zheng" <zheng.z.yan@intel.com>
To: unlisted-recipients:; (no To-header on input)
Cc: linux-btrfs@vger.kernel.org
Subject: [PATCH] btrfs: check file extent backref offset underflow
Date: Mon, 29 Aug 2011 09:25:53 +0800 [thread overview]
Message-ID: <4E5AEAA1.1070200@intel.com> (raw)
Offset field in data extent backref can underflow if clone range ioctl
is used. We can reliably detect the underflow because max file size is
limited to 2^63 and max data extent size is limited by block group size.
Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
---
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 59bb176..107c9cf 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -3323,8 +3323,11 @@ static int find_data_references(struct reloc_control *rc,
}
key.objectid = ref_objectid;
- key.offset = ref_offset;
key.type = BTRFS_EXTENT_DATA_KEY;
+ if (ref_offset > ((u64)-1 << 32))
+ key.offset = 0;
+ else
+ key.offset = ref_offset;
path->search_commit_root = 1;
path->skip_locking = 1;
next reply other threads:[~2011-08-29 1:25 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-29 1:25 Yan, Zheng [this message]
2011-08-29 1:59 ` [PATCH] btrfs: check file extent backref offset underflow Li Zefan
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