From 84850e8d8a5ec7b9d3c47d224e9a10c9da52ff1b Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Mon, 29 Aug 2011 09:25:53 +0800 Subject: [PATCH] btrfs: check file extent backref offset underflow 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 --- fs/btrfs/relocation.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 10af6a0..24d654c 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -3322,8 +3322,11 @@ 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; -- 2.7.4