linux/fs/bcachefs/sb-downgrade.c
Kent Overstreet 692aa7a54b bcachefs: Fix sb_field_downgrade validation
- bch2_sb_downgrade_validate() wasn't checking for a downgrade entry
  extending past the end of the superblock section

- for_each_downgrade_entry() is used in to_text() and needs to work on
  malformed input; it also was missing a check for a field extending
  past the end of the section

Reported-by: syzbot+e49ccab73449180bc9be@syzkaller.appspotmail.com
Fixes: 84f1638795 ("bcachefs: bch_sb_field_downgrade")
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-05-09 16:23:36 -04:00

277 lines
8.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Superblock section that contains a list of recovery passes to run when
* downgrading past a given version
*/
#include "bcachefs.h"
#include "darray.h"
#include "recovery_passes.h"
#include "sb-downgrade.h"
#include "sb-errors.h"
#include "super-io.h"
#define RECOVERY_PASS_ALL_FSCK BIT_ULL(63)
/*
* Upgrade, downgrade tables - run certain recovery passes, fix certain errors
*
* x(version, recovery_passes, errors...)
*/
#define UPGRADE_TABLE() \
x(backpointers, \
RECOVERY_PASS_ALL_FSCK) \
x(inode_v3, \
RECOVERY_PASS_ALL_FSCK) \
x(unwritten_extents, \
RECOVERY_PASS_ALL_FSCK) \
x(bucket_gens, \
BIT_ULL(BCH_RECOVERY_PASS_bucket_gens_init)| \
RECOVERY_PASS_ALL_FSCK) \
x(lru_v2, \
RECOVERY_PASS_ALL_FSCK) \
x(fragmentation_lru, \
RECOVERY_PASS_ALL_FSCK) \
x(no_bps_in_alloc_keys, \
RECOVERY_PASS_ALL_FSCK) \
x(snapshot_trees, \
RECOVERY_PASS_ALL_FSCK) \
x(snapshot_skiplists, \
BIT_ULL(BCH_RECOVERY_PASS_check_snapshots), \
BCH_FSCK_ERR_snapshot_bad_depth, \
BCH_FSCK_ERR_snapshot_bad_skiplist) \
x(deleted_inodes, \
BIT_ULL(BCH_RECOVERY_PASS_check_inodes), \
BCH_FSCK_ERR_unlinked_inode_not_on_deleted_list) \
x(rebalance_work, \
BIT_ULL(BCH_RECOVERY_PASS_set_fs_needs_rebalance)) \
x(subvolume_fs_parent, \
BIT_ULL(BCH_RECOVERY_PASS_check_dirents), \
BCH_FSCK_ERR_subvol_fs_path_parent_wrong) \
x(btree_subvolume_children, \
BIT_ULL(BCH_RECOVERY_PASS_check_subvols), \
BCH_FSCK_ERR_subvol_children_not_set) \
x(mi_btree_bitmap, \
BIT_ULL(BCH_RECOVERY_PASS_check_allocations), \
BCH_FSCK_ERR_btree_bitmap_not_marked)
#define DOWNGRADE_TABLE()
struct upgrade_downgrade_entry {
u64 recovery_passes;
u16 version;
u16 nr_errors;
const u16 *errors;
};
#define x(ver, passes, ...) static const u16 upgrade_##ver##_errors[] = { __VA_ARGS__ };
UPGRADE_TABLE()
#undef x
static const struct upgrade_downgrade_entry upgrade_table[] = {
#define x(ver, passes, ...) { \
.recovery_passes = passes, \
.version = bcachefs_metadata_version_##ver,\
.nr_errors = ARRAY_SIZE(upgrade_##ver##_errors), \
.errors = upgrade_##ver##_errors, \
},
UPGRADE_TABLE()
#undef x
};
void bch2_sb_set_upgrade(struct bch_fs *c,
unsigned old_version,
unsigned new_version)
{
lockdep_assert_held(&c->sb_lock);
struct bch_sb_field_ext *ext = bch2_sb_field_get(c->disk_sb.sb, ext);
for (const struct upgrade_downgrade_entry *i = upgrade_table;
i < upgrade_table + ARRAY_SIZE(upgrade_table);
i++)
if (i->version > old_version && i->version <= new_version) {
u64 passes = i->recovery_passes;
if (passes & RECOVERY_PASS_ALL_FSCK)
passes |= bch2_fsck_recovery_passes();
passes &= ~RECOVERY_PASS_ALL_FSCK;
ext->recovery_passes_required[0] |=
cpu_to_le64(bch2_recovery_passes_to_stable(passes));
for (const u16 *e = i->errors;
e < i->errors + i->nr_errors;
e++) {
__set_bit(*e, c->sb.errors_silent);
ext->errors_silent[*e / 64] |= cpu_to_le64(BIT_ULL(*e % 64));
}
}
}
#define x(ver, passes, ...) static const u16 downgrade_ver_##errors[] = { __VA_ARGS__ };
DOWNGRADE_TABLE()
#undef x
static const struct upgrade_downgrade_entry downgrade_table[] = {
#define x(ver, passes, ...) { \
.recovery_passes = passes, \
.version = bcachefs_metadata_version_##ver,\
.nr_errors = ARRAY_SIZE(downgrade_##ver##_errors), \
.errors = downgrade_##ver##_errors, \
},
DOWNGRADE_TABLE()
#undef x
};
static inline const struct bch_sb_field_downgrade_entry *
downgrade_entry_next_c(const struct bch_sb_field_downgrade_entry *e)
{
return (void *) &e->errors[le16_to_cpu(e->nr_errors)];
}
#define for_each_downgrade_entry(_d, _i) \
for (const struct bch_sb_field_downgrade_entry *_i = (_d)->entries; \
(void *) _i < vstruct_end(&(_d)->field) && \
(void *) &_i->errors[0] <= vstruct_end(&(_d)->field) && \
(void *) downgrade_entry_next_c(_i) <= vstruct_end(&(_d)->field); \
_i = downgrade_entry_next_c(_i))
static int bch2_sb_downgrade_validate(struct bch_sb *sb, struct bch_sb_field *f,
enum bch_validate_flags flags, struct printbuf *err)
{
struct bch_sb_field_downgrade *e = field_to_type(f, downgrade);
for (const struct bch_sb_field_downgrade_entry *i = e->entries;
(void *) i < vstruct_end(&e->field);
i = downgrade_entry_next_c(i)) {
if (flags & BCH_VALIDATE_write &&
((void *) &i->errors[0] > vstruct_end(&e->field) ||
(void *) downgrade_entry_next_c(i) > vstruct_end(&e->field))) {
prt_printf(err, "downgrade entry overruns end of superblock section)");
return -BCH_ERR_invalid_sb_downgrade;
}
if (BCH_VERSION_MAJOR(le16_to_cpu(i->version)) !=
BCH_VERSION_MAJOR(le16_to_cpu(sb->version))) {
prt_printf(err, "downgrade entry with mismatched major version (%u != %u)",
BCH_VERSION_MAJOR(le16_to_cpu(i->version)),
BCH_VERSION_MAJOR(le16_to_cpu(sb->version)));
return -BCH_ERR_invalid_sb_downgrade;
}
}
return 0;
}
static void bch2_sb_downgrade_to_text(struct printbuf *out, struct bch_sb *sb,
struct bch_sb_field *f)
{
struct bch_sb_field_downgrade *e = field_to_type(f, downgrade);
if (out->nr_tabstops <= 1)
printbuf_tabstop_push(out, 16);
for_each_downgrade_entry(e, i) {
prt_str(out, "version:\t");
bch2_version_to_text(out, le16_to_cpu(i->version));
prt_newline(out);
prt_str(out, "recovery passes:\t");
prt_bitflags(out, bch2_recovery_passes,
bch2_recovery_passes_from_stable(le64_to_cpu(i->recovery_passes[0])));
prt_newline(out);
prt_str(out, "errors:\t");
bool first = true;
for (unsigned j = 0; j < le16_to_cpu(i->nr_errors); j++) {
if (!first)
prt_char(out, ',');
first = false;
unsigned e = le16_to_cpu(i->errors[j]);
prt_str(out, e < BCH_SB_ERR_MAX ? bch2_sb_error_strs[e] : "(unknown)");
}
prt_newline(out);
}
}
const struct bch_sb_field_ops bch_sb_field_ops_downgrade = {
.validate = bch2_sb_downgrade_validate,
.to_text = bch2_sb_downgrade_to_text,
};
int bch2_sb_downgrade_update(struct bch_fs *c)
{
darray_char table = {};
int ret = 0;
for (const struct upgrade_downgrade_entry *src = downgrade_table;
src < downgrade_table + ARRAY_SIZE(downgrade_table);
src++) {
if (BCH_VERSION_MAJOR(src->version) != BCH_VERSION_MAJOR(le16_to_cpu(c->disk_sb.sb->version)))
continue;
struct bch_sb_field_downgrade_entry *dst;
unsigned bytes = sizeof(*dst) + sizeof(dst->errors[0]) * src->nr_errors;
ret = darray_make_room(&table, bytes);
if (ret)
goto out;
dst = (void *) &darray_top(table);
dst->version = cpu_to_le16(src->version);
dst->recovery_passes[0] = cpu_to_le64(src->recovery_passes);
dst->recovery_passes[1] = 0;
dst->nr_errors = cpu_to_le16(src->nr_errors);
for (unsigned i = 0; i < src->nr_errors; i++)
dst->errors[i] = cpu_to_le16(src->errors[i]);
table.nr += bytes;
}
struct bch_sb_field_downgrade *d = bch2_sb_field_get(c->disk_sb.sb, downgrade);
unsigned sb_u64s = DIV_ROUND_UP(sizeof(*d) + table.nr, sizeof(u64));
if (d && le32_to_cpu(d->field.u64s) > sb_u64s)
goto out;
d = bch2_sb_field_resize(&c->disk_sb, downgrade, sb_u64s);
if (!d) {
ret = -BCH_ERR_ENOSPC_sb_downgrade;
goto out;
}
memcpy(d->entries, table.data, table.nr);
memset_u64s_tail(d->entries, 0, table.nr);
out:
darray_exit(&table);
return ret;
}
void bch2_sb_set_downgrade(struct bch_fs *c, unsigned new_minor, unsigned old_minor)
{
struct bch_sb_field_downgrade *d = bch2_sb_field_get(c->disk_sb.sb, downgrade);
if (!d)
return;
struct bch_sb_field_ext *ext = bch2_sb_field_get(c->disk_sb.sb, ext);
for_each_downgrade_entry(d, i) {
unsigned minor = BCH_VERSION_MINOR(le16_to_cpu(i->version));
if (new_minor < minor && minor <= old_minor) {
ext->recovery_passes_required[0] |= i->recovery_passes[0];
ext->recovery_passes_required[1] |= i->recovery_passes[1];
for (unsigned j = 0; j < le16_to_cpu(i->nr_errors); j++) {
unsigned e = le16_to_cpu(i->errors[j]);
if (e < BCH_SB_ERR_MAX)
__set_bit(e, c->sb.errors_silent);
if (e < sizeof(ext->errors_silent) * 8)
__set_bit_le64(e, ext->errors_silent);
}
}
}
}