diff options
| author | Kent Overstreet | 2024-05-05 22:44:27 -0400 |
|---|---|---|
| committer | Kent Overstreet | 2024-05-06 10:58:17 -0400 |
| commit | 0ec5b3b7ccfcdca02ab322abf86455d0050ae98f (patch) | |
| tree | bddfe9cbcf667bc47fbdd3aa9e5d06cfdf420366 /fs | |
| parent | 2bb9600d5d4735953c47dd1ee99382c68dd04caa (diff) | |
bcachefs: Fix shift-by-64 in bformat_needs_redo()
Ancient versions of bcachefs produced packed formats that could
represent keys that our in memory format cannot represent;
bformat_needs_redo() has some tricky shifts to check for this sort of
overflow.
Reported-by: syzbot+594427aebfefeebe91c6@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/bcachefs/move.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/fs/bcachefs/move.c b/fs/bcachefs/move.c index bf68ea49447b..4d94b7742dbb 100644 --- a/fs/bcachefs/move.c +++ b/fs/bcachefs/move.c @@ -968,24 +968,30 @@ static bool migrate_btree_pred(struct bch_fs *c, void *arg, return migrate_pred(c, arg, bkey_i_to_s_c(&b->key), io_opts, data_opts); } +/* + * Ancient versions of bcachefs produced packed formats which could represent + * keys that the in memory format cannot represent; this checks for those + * formats so we can get rid of them. + */ static bool bformat_needs_redo(struct bkey_format *f) { - unsigned i; - - for (i = 0; i < f->nr_fields; i++) { + for (unsigned i = 0; i < f->nr_fields; i++) { + unsigned f_bits = f->bits_per_field[i]; unsigned unpacked_bits = bch2_bkey_format_current.bits_per_field[i]; u64 unpacked_mask = ~((~0ULL << 1) << (unpacked_bits - 1)); u64 field_offset = le64_to_cpu(f->field_offset[i]); - if (f->bits_per_field[i] > unpacked_bits) + if (f_bits > unpacked_bits) return true; - if ((f->bits_per_field[i] == unpacked_bits) && field_offset) + if ((f_bits == unpacked_bits) && field_offset) return true; - if (((field_offset + ((1ULL << f->bits_per_field[i]) - 1)) & - unpacked_mask) < - field_offset) + u64 f_mask = f_bits + ? ~((~0ULL << (f_bits - 1)) << 1) + : 0; + + if (((field_offset + f_mask) & unpacked_mask) < field_offset) return true; } |