btrfs: tree-checker: validate number of chunk stripes and parity

If there's no parity and num_stripes < ncopies, a crafted image can
trigger a division by zero in calc_stripe_length().

The image was generated through fuzzing.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=209587
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Daniel Xu 2020-10-08 18:09:10 -07:00 committed by David Sterba
parent cad69d1396
commit 85d07fbe09

View File

@ -760,18 +760,36 @@ int btrfs_check_chunk_valid(struct extent_buffer *leaf,
u64 type;
u64 features;
bool mixed = false;
int raid_index;
int nparity;
int ncopies;
length = btrfs_chunk_length(leaf, chunk);
stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
type = btrfs_chunk_type(leaf, chunk);
raid_index = btrfs_bg_flags_to_raid_index(type);
ncopies = btrfs_raid_array[raid_index].ncopies;
nparity = btrfs_raid_array[raid_index].nparity;
if (!num_stripes) {
chunk_err(leaf, chunk, logical,
"invalid chunk num_stripes, have %u", num_stripes);
return -EUCLEAN;
}
if (num_stripes < ncopies) {
chunk_err(leaf, chunk, logical,
"invalid chunk num_stripes < ncopies, have %u < %d",
num_stripes, ncopies);
return -EUCLEAN;
}
if (nparity && num_stripes == nparity) {
chunk_err(leaf, chunk, logical,
"invalid chunk num_stripes == nparity, have %u == %d",
num_stripes, nparity);
return -EUCLEAN;
}
if (!IS_ALIGNED(logical, fs_info->sectorsize)) {
chunk_err(leaf, chunk, logical,
"invalid chunk logical, have %llu should aligned to %u",