diff options
| -rw-r--r-- | drivers/md/dm-verity-fec.c | 11 | ||||
| -rw-r--r-- | drivers/md/dm-verity-fec.h | 4 |
2 files changed, 14 insertions, 1 deletions
diff --git a/drivers/md/dm-verity-fec.c b/drivers/md/dm-verity-fec.c index ad10d6d8ed28..b26809a47ca3 100644 --- a/drivers/md/dm-verity-fec.c +++ b/drivers/md/dm-verity-fec.c @@ -442,6 +442,13 @@ int verity_fec_decode(struct dm_verity *v, struct dm_verity_io *io, if (!verity_fec_is_enabled(v)) return -EOPNOTSUPP; + if (fio->level >= DM_VERITY_FEC_MAX_RECURSION) { + DMWARN_LIMIT("%s: FEC: recursion too deep", v->data_dev->name); + return -EIO; + } + + fio->level++; + if (type == DM_VERITY_BLOCK_TYPE_METADATA) block += v->data_blocks; @@ -475,7 +482,7 @@ int verity_fec_decode(struct dm_verity *v, struct dm_verity_io *io, if (r < 0) { r = fec_decode_rsb(v, io, fio, rsb, offset, true); if (r < 0) - return r; + goto done; } if (dest) @@ -485,6 +492,8 @@ int verity_fec_decode(struct dm_verity *v, struct dm_verity_io *io, r = verity_for_bv_block(v, io, iter, fec_bv_copy); } +done: + fio->level--; return r; } diff --git a/drivers/md/dm-verity-fec.h b/drivers/md/dm-verity-fec.h index 8c4bee052a73..b8e21cef3ad1 100644 --- a/drivers/md/dm-verity-fec.h +++ b/drivers/md/dm-verity-fec.h @@ -28,6 +28,9 @@ #define DM_VERITY_FEC_BUF_MAX \ (1 << (PAGE_SHIFT - DM_VERITY_FEC_BUF_RS_BITS)) +/* maximum recursion level for verity_fec_decode */ +#define DM_VERITY_FEC_MAX_RECURSION 4 + #define DM_VERITY_OPT_FEC_DEV "use_fec_from_device" #define DM_VERITY_OPT_FEC_BLOCKS "fec_blocks" #define DM_VERITY_OPT_FEC_START "fec_start" @@ -61,6 +64,7 @@ struct dm_verity_fec_io { unsigned nbufs; /* number of buffers allocated */ u8 *output; /* buffer for corrected output */ size_t output_pos; + unsigned level; /* recursion level */ }; #ifdef CONFIG_DM_VERITY_FEC |