diff options
Diffstat (limited to 'fs/btrfs/lzo.c')
| -rw-r--r-- | fs/btrfs/lzo.c | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c index 9591927022ba..464fbb96af1a 100644 --- a/fs/btrfs/lzo.c +++ b/fs/btrfs/lzo.c @@ -295,6 +295,7 @@ static int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb) unsigned long working_bytes; size_t in_len; size_t out_len; + const size_t max_segment_len = lzo1x_worst_compress(PAGE_SIZE); unsigned long in_offset; unsigned long in_page_bytes_left; unsigned long tot_in; @@ -308,10 +309,22 @@ static int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb) data_in = kmap(pages_in[0]); tot_len = read_compress_length(data_in); + /* + * Compressed data header check. + * + * The real compressed size can't exceed the maximum extent length, and + * all pages should be used (whole unused page with just the segment + * header is not possible). If this happens it means the compressed + * extent is corrupted. + */ + if (tot_len > min_t(size_t, BTRFS_MAX_COMPRESSED, srclen) || + tot_len < srclen - PAGE_SIZE) { + ret = -EUCLEAN; + goto done; + } tot_in = LZO_LEN; in_offset = LZO_LEN; - tot_len = min_t(size_t, srclen, tot_len); in_page_bytes_left = PAGE_SIZE - LZO_LEN; tot_out = 0; @@ -322,6 +335,17 @@ static int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb) in_offset += LZO_LEN; tot_in += LZO_LEN; + /* + * Segment header check. + * + * The segment length must not exceed the maximum LZO + * compression size, nor the total compressed size. + */ + if (in_len > max_segment_len || tot_in + in_len > tot_len) { + ret = -EUCLEAN; + goto done; + } + tot_in += in_len; working_bytes = in_len; may_late_unmap = need_unmap = false; @@ -372,7 +396,7 @@ cont: } } - out_len = lzo1x_worst_compress(PAGE_SIZE); + out_len = max_segment_len; ret = lzo1x_decompress_safe(buf, in_len, workspace->buf, &out_len); if (need_unmap) |