bcachefs: Fix shift greater than integer size

Reported-by: syzbot+e5292b50f1957164a4b6@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/bkey.c b/fs/bcachefs/bkey.c
index 94a1d1982fa8890c5efb2175a95dbdbabf93ef03..587d7318a2e81aa670c0a98143afd57cf4bfde2f 100644 (file)
--- a/fs/bcachefs/bkey.c
+++ b/fs/bcachefs/bkey.c
@@ -660,8 +660,9 @@ int bch2_bkey_format_invalid(struct bch_fs *c,
                    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));
-                       u64 packed_max = f->bits_per_field[i]
-                               ? ~((~0ULL << 1) << (f->bits_per_field[i] - 1))
+                       unsigned packed_bits = min(64, f->bits_per_field[i]);
+                       u64 packed_max = packed_bits
+                               ? ~((~0ULL << 1) << (packed_bits - 1))
                                : 0;
 
                        prt_printf(err, "field %u too large: %llu + %llu > %llu",