From: Daniel Xu dxu@dxuuu.xyz
commit 85d07fbe09efd1c529ff3e025e2f0d2c6c96a1b7 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/btrfs/tree-checker.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
--- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -577,18 +577,36 @@ int btrfs_check_chunk_valid(struct exten 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",