From d335bb3fd3a4102f325ef8a353efc3d2fb523f55 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Thu, 31 Oct 2024 02:36:21 -0400 Subject: [PATCH] bcachefs: Ancient versions with bad bkey_formats are no longer supported Syzbot found an assertion pop, by generating an ancient filesystem version with an invalid bkey_format (with fields that can overflow) as well as packed keys that aren't representable unpacked. This breaks key comparisons in all sorts of painful ways. Filesystems have been automatically rewriting nodes with such invalid formats for years; we can safely drop support for them. Reported-by: syzbot+8a0109511de9d4b61217@syzkaller.appspotmail.com Signed-off-by: Kent Overstreet --- fs/bcachefs/bkey.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/bcachefs/bkey.c b/fs/bcachefs/bkey.c index 587d7318a2e8..995ba32e9b6e 100644 --- a/fs/bcachefs/bkey.c +++ b/fs/bcachefs/bkey.c @@ -643,7 +643,7 @@ int bch2_bkey_format_invalid(struct bch_fs *c, enum bch_validate_flags flags, struct printbuf *err) { - unsigned i, bits = KEY_PACKED_BITS_START; + unsigned bits = KEY_PACKED_BITS_START; if (f->nr_fields != BKEY_NR_FIELDS) { prt_printf(err, "incorrect number of fields: got %u, should be %u", @@ -655,9 +655,8 @@ int bch2_bkey_format_invalid(struct bch_fs *c, * Verify that the packed format can't represent fields larger than the * unpacked format: */ - for (i = 0; i < f->nr_fields; i++) { - if ((!c || c->sb.version_min >= bcachefs_metadata_version_snapshot) && - bch2_bkey_format_field_overflows(f, i)) { + for (unsigned i = 0; i < f->nr_fields; i++) { + if (bch2_bkey_format_field_overflows(f, i)) { unsigned unpacked_bits = bch2_bkey_format_current.bits_per_field[i]; u64 unpacked_max = ~((~0ULL << 1) << (unpacked_bits - 1)); unsigned packed_bits = min(64, f->bits_per_field[i]);