A check for a valid value for bits_per_field is performed for each field before computing packed_max. If bits_per_field is invalid for any field the whole format is deemed invalid.
Reported-by: [email protected] Signed-off-by: Camila Alvarez <[email protected]> --- fs/bcachefs/bcachefs_format.h | 8 ++++++++ fs/bcachefs/bkey.c | 18 ++++++++++++++++-- 2 files changed, 24 insertions(+), 2 deletions(-) diff --git a/fs/bcachefs/bcachefs_format.h b/fs/bcachefs/bcachefs_format.h index d5b90439e581..9e688a8d780f 100644 --- a/fs/bcachefs/bcachefs_format.h +++ b/fs/bcachefs/bcachefs_format.h @@ -318,6 +318,14 @@ enum bch_bkey_fields { #define bkey_format_field(name, field) \ [BKEY_FIELD_##name] = (sizeof(((struct bkey *) NULL)->field) * 8) +#define BCH_BKEY_FIELDS() \ + x(INODE, p.inode) \ + x(OFFSET, p.offset) \ + x(SNAPSHOT, p.snapshot) \ + x(SIZE, size) \ + x(VERSION_HI, version.hi) \ + x(VERSION_LO, version.lo) + #define BKEY_FORMAT_CURRENT \ ((struct bkey_format) { \ .key_u64s = BKEY_U64s, \ diff --git a/fs/bcachefs/bkey.c b/fs/bcachefs/bkey.c index 76e79a15ba08..f7847c96a105 100644 --- a/fs/bcachefs/bkey.c +++ b/fs/bcachefs/bkey.c @@ -638,6 +638,13 @@ struct bkey_format bch2_bkey_format_done(struct bkey_format_state *s) return ret; } +static unsigned bch2_max_bits_per_field[] = { +#define x(name, field) \ + bkey_format_field(name, field), + BCH_BKEY_FIELDS() +#undef x +}; + int bch2_bkey_format_invalid(struct bch_fs *c, struct bkey_format *f, enum bkey_invalid_flags flags, @@ -659,8 +666,15 @@ int bch2_bkey_format_invalid(struct bch_fs *c, if (!c || c->sb.version_min >= bcachefs_metadata_version_snapshot) { unsigned unpacked_bits = bch2_bkey_format_current.bits_per_field[i]; u64 unpacked_max = ~((~0ULL << 1) << (unpacked_bits - 1)); - u64 packed_max = f->bits_per_field[i] - ? ~((~0ULL << 1) << (f->bits_per_field[i] - 1)) + unsigned bits_per_field = f->bits_per_field[i]; + + if (bits_per_field > bch2_max_bits_per_field[i]) { + prt_printf(err, "field %u uses more bits than allowed: %u > %u", + i, bits_per_field, bch2_max_bits_per_field[i]); + return -BCH_ERR_invalid; + } + u64 packed_max = bits_per_field + ? ~((~0ULL << 1) << (bits_per_field - 1)) : 0; u64 field_offset = le64_to_cpu(f->field_offset[i]); -- 2.34.1
