4.14-stable review patch. If anyone has any objections, please let me know.
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From: Qu Wenruo wqu@suse.com
[ Upstream commit 64f64f43c89aca1782aa672e0586f6903c5d8979 ]
It's entirely possible that a crafted btrfs image contains overlapping chunks.
Although we can't detect such problem by tree-checker, it's not a catastrophic problem, current extent map can already detect such problem and return -EEXIST.
We just only need to exit gracefully and fail the mount.
Reported-by: Xu Wen wen.xu@gatech.edu Link: https://bugzilla.kernel.org/show_bug.cgi?id=200409 Signed-off-by: Qu Wenruo wqu@suse.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/volumes.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
--- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6492,10 +6492,14 @@ static int read_one_chunk(struct btrfs_f write_lock(&map_tree->map_tree.lock); ret = add_extent_mapping(&map_tree->map_tree, em, 0); write_unlock(&map_tree->map_tree.lock); - BUG_ON(ret); /* Tree corruption */ + if (ret < 0) { + btrfs_err(fs_info, + "failed to add chunk map, start=%llu len=%llu: %d", + em->start, em->len, ret); + } free_extent_map(em);
- return 0; + return ret; }
static void fill_device_from_item(struct extent_buffer *leaf,