3.16.83-rc1 review patch. If anyone has any objections, please let me know.
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From: David Sterba dsterba@suse.cz
commit e3540eab29e1b2260bc4b9b3979a49a00e3e3af8 upstream.
Verify that the sys_array has enough bytes to read the next item.
Signed-off-by: David Sterba dsterba@suse.cz Signed-off-by: Chris Mason clm@fb.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- fs/btrfs/volumes.c | 26 +++++++++++++++++++++++--- 1 file changed, 23 insertions(+), 3 deletions(-)
--- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6071,20 +6071,34 @@ int btrfs_read_sys_array(struct btrfs_ro
while (cur_offset < array_size) { disk_key = (struct btrfs_disk_key *)array_ptr; + len = sizeof(*disk_key); + if (cur_offset + len > array_size) + goto out_short_read; + btrfs_disk_key_to_cpu(&key, disk_key);
- len = sizeof(*disk_key); array_ptr += len; sb_array_offset += len; cur_offset += len;
if (key.type == BTRFS_CHUNK_ITEM_KEY) { chunk = (struct btrfs_chunk *)sb_array_offset; + /* + * At least one btrfs_chunk with one stripe must be + * present, exact stripe count check comes afterwards + */ + len = btrfs_chunk_item_size(1); + if (cur_offset + len > array_size) + goto out_short_read; + + num_stripes = btrfs_chunk_num_stripes(sb, chunk); + len = btrfs_chunk_item_size(num_stripes); + if (cur_offset + len > array_size) + goto out_short_read; + ret = read_one_chunk(root, &key, sb, chunk); if (ret) break; - num_stripes = btrfs_chunk_num_stripes(sb, chunk); - len = btrfs_chunk_item_size(num_stripes); } else { ret = -EIO; break; @@ -6095,6 +6109,12 @@ int btrfs_read_sys_array(struct btrfs_ro } free_extent_buffer(sb); return ret; + +out_short_read: + printk(KERN_ERR "BTRFS: sys_array too short to read %u bytes at offset %u\n", + len, cur_offset); + free_extent_buffer(sb); + return -EIO; }
int btrfs_read_chunk_tree(struct btrfs_root *root)