[PATCH 5.16 0845/1039] md: Move alloc/free acct bioset in to personality

From: Greg Kroah-Hartman
Date: Mon Jan 24 2022 - 19:30:07 EST


From: Xiao Ni <xni@xxxxxxxxxx>

commit 0c031fd37f69deb0cd8c43bbfcfccd62ebd7e952 upstream.

bioset acct is only needed for raid0 and raid5. Therefore, md_run only
allocates it for raid0 and raid5. However, this does not cover
personality takeover, which may cause uninitialized bioset. For example,
the following repro steps:

mdadm -CR /dev/md0 -l1 -n2 /dev/loop0 /dev/loop1
mdadm --wait /dev/md0
mkfs.xfs /dev/md0
mdadm /dev/md0 --grow -l5
mount /dev/md0 /mnt

causes panic like:

[ 225.933939] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 225.934903] #PF: supervisor instruction fetch in kernel mode
[ 225.935639] #PF: error_code(0x0010) - not-present page
[ 225.936361] PGD 0 P4D 0
[ 225.936677] Oops: 0010 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN PTI
[ 225.937525] CPU: 27 PID: 1133 Comm: mount Not tainted 5.16.0-rc3+ #706
[ 225.938416] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.module_el8.4.0+547+a85d02ba 04/01/2014
[ 225.939922] RIP: 0010:0x0
[ 225.940289] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
[ 225.941196] RSP: 0018:ffff88815897eff0 EFLAGS: 00010246
[ 225.941897] RAX: 0000000000000000 RBX: 0000000000092800 RCX: ffffffff81370a39
[ 225.942813] RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000092800
[ 225.943772] RBP: 1ffff1102b12fe04 R08: fffffbfff0b43c01 R09: fffffbfff0b43c01
[ 225.944807] R10: ffffffff85a1e007 R11: fffffbfff0b43c00 R12: ffff88810eaaaf58
[ 225.945757] R13: 0000000000000000 R14: ffff88810eaaafb8 R15: ffff88815897f040
[ 225.946709] FS: 00007ff3f2505080(0000) GS:ffff888fb5e00000(0000) knlGS:0000000000000000
[ 225.947814] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 225.948556] CR2: ffffffffffffffd6 CR3: 000000015aa5a006 CR4: 0000000000370ee0
[ 225.949537] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 225.950455] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 225.951414] Call Trace:
[ 225.951787] <TASK>
[ 225.952120] mempool_alloc+0xe5/0x250
[ 225.952625] ? mempool_resize+0x370/0x370
[ 225.953187] ? rcu_read_lock_sched_held+0xa1/0xd0
[ 225.953862] ? rcu_read_lock_bh_held+0xb0/0xb0
[ 225.954464] ? sched_clock_cpu+0x15/0x120
[ 225.955019] ? find_held_lock+0xac/0xd0
[ 225.955564] bio_alloc_bioset+0x1ed/0x2a0
[ 225.956080] ? lock_downgrade+0x3a0/0x3a0
[ 225.956644] ? bvec_alloc+0xc0/0xc0
[ 225.957135] bio_clone_fast+0x19/0x80
[ 225.957651] raid5_make_request+0x1370/0x1b70
[ 225.958286] ? sched_clock_cpu+0x15/0x120
[ 225.958797] ? __lock_acquire+0x8b2/0x3510
[ 225.959339] ? raid5_get_active_stripe+0xce0/0xce0
[ 225.959986] ? lock_is_held_type+0xd8/0x130
[ 225.960528] ? rcu_read_lock_sched_held+0xa1/0xd0
[ 225.961135] ? rcu_read_lock_bh_held+0xb0/0xb0
[ 225.961703] ? sched_clock_cpu+0x15/0x120
[ 225.962232] ? lock_release+0x27a/0x6c0
[ 225.962746] ? do_wait_intr_irq+0x130/0x130
[ 225.963302] ? lock_downgrade+0x3a0/0x3a0
[ 225.963815] ? lock_release+0x6c0/0x6c0
[ 225.964348] md_handle_request+0x342/0x530
[ 225.964888] ? set_in_sync+0x170/0x170
[ 225.965397] ? blk_queue_split+0x133/0x150
[ 225.965988] ? __blk_queue_split+0x8b0/0x8b0
[ 225.966524] ? submit_bio_checks+0x3b2/0x9d0
[ 225.967069] md_submit_bio+0x127/0x1c0
[...]

Fix this by moving alloc/free of acct bioset to pers->run and pers->free.

While we are on this, properly handle md_integrity_register() error in
raid0_run().

Fixes: daee2024715d (md: check level before create and exit io_acct_set)
Cc: stable@xxxxxxxxxxxxxxx
Acked-by: Guoqing Jiang <guoqing.jiang@xxxxxxxxx>
Signed-off-by: Xiao Ni <xni@xxxxxxxxxx>
Signed-off-by: Song Liu <song@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/md.c | 27 +++++++++++++++++----------
drivers/md/md.h | 2 ++
drivers/md/raid0.c | 38 ++++++++++++++++++++++++++++----------
drivers/md/raid5.c | 41 ++++++++++++++++++++++++++++++-----------
4 files changed, 77 insertions(+), 31 deletions(-)

--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5875,13 +5875,6 @@ int md_run(struct mddev *mddev)
if (err)
goto exit_bio_set;
}
- if (mddev->level != 1 && mddev->level != 10 &&
- !bioset_initialized(&mddev->io_acct_set)) {
- err = bioset_init(&mddev->io_acct_set, BIO_POOL_SIZE,
- offsetof(struct md_io_acct, bio_clone), 0);
- if (err)
- goto exit_sync_set;
- }

spin_lock(&pers_lock);
pers = find_pers(mddev->level, mddev->clevel);
@@ -6058,9 +6051,6 @@ bitmap_abort:
module_put(pers->owner);
md_bitmap_destroy(mddev);
abort:
- if (mddev->level != 1 && mddev->level != 10)
- bioset_exit(&mddev->io_acct_set);
-exit_sync_set:
bioset_exit(&mddev->sync_set);
exit_bio_set:
bioset_exit(&mddev->bio_set);
@@ -8594,6 +8584,23 @@ void md_submit_discard_bio(struct mddev
}
EXPORT_SYMBOL_GPL(md_submit_discard_bio);

+int acct_bioset_init(struct mddev *mddev)
+{
+ int err = 0;
+
+ if (!bioset_initialized(&mddev->io_acct_set))
+ err = bioset_init(&mddev->io_acct_set, BIO_POOL_SIZE,
+ offsetof(struct md_io_acct, bio_clone), 0);
+ return err;
+}
+EXPORT_SYMBOL_GPL(acct_bioset_init);
+
+void acct_bioset_exit(struct mddev *mddev)
+{
+ bioset_exit(&mddev->io_acct_set);
+}
+EXPORT_SYMBOL_GPL(acct_bioset_exit);
+
static void md_end_io_acct(struct bio *bio)
{
struct md_io_acct *md_io_acct = bio->bi_private;
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -721,6 +721,8 @@ extern void md_error(struct mddev *mddev
extern void md_finish_reshape(struct mddev *mddev);
void md_submit_discard_bio(struct mddev *mddev, struct md_rdev *rdev,
struct bio *bio, sector_t start, sector_t size);
+int acct_bioset_init(struct mddev *mddev);
+void acct_bioset_exit(struct mddev *mddev);
void md_account_bio(struct mddev *mddev, struct bio **bio);

extern bool __must_check md_flush_request(struct mddev *mddev, struct bio *bio);
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -356,7 +356,21 @@ static sector_t raid0_size(struct mddev
return array_sectors;
}

-static void raid0_free(struct mddev *mddev, void *priv);
+static void free_conf(struct mddev *mddev, struct r0conf *conf)
+{
+ kfree(conf->strip_zone);
+ kfree(conf->devlist);
+ kfree(conf);
+ mddev->private = NULL;
+}
+
+static void raid0_free(struct mddev *mddev, void *priv)
+{
+ struct r0conf *conf = priv;
+
+ free_conf(mddev, conf);
+ acct_bioset_exit(mddev);
+}

static int raid0_run(struct mddev *mddev)
{
@@ -370,11 +384,16 @@ static int raid0_run(struct mddev *mddev
if (md_check_no_bitmap(mddev))
return -EINVAL;

+ if (acct_bioset_init(mddev)) {
+ pr_err("md/raid0:%s: alloc acct bioset failed.\n", mdname(mddev));
+ return -ENOMEM;
+ }
+
/* if private is not null, we are here after takeover */
if (mddev->private == NULL) {
ret = create_strip_zones(mddev, &conf);
if (ret < 0)
- return ret;
+ goto exit_acct_set;
mddev->private = conf;
}
conf = mddev->private;
@@ -413,17 +432,16 @@ static int raid0_run(struct mddev *mddev
dump_zones(mddev);

ret = md_integrity_register(mddev);
+ if (ret)
+ goto free;

return ret;
-}

-static void raid0_free(struct mddev *mddev, void *priv)
-{
- struct r0conf *conf = priv;
-
- kfree(conf->strip_zone);
- kfree(conf->devlist);
- kfree(conf);
+free:
+ free_conf(mddev, conf);
+exit_acct_set:
+ acct_bioset_exit(mddev);
+ return ret;
}

static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -7446,12 +7446,19 @@ static int raid5_run(struct mddev *mddev
struct md_rdev *rdev;
struct md_rdev *journal_dev = NULL;
sector_t reshape_offset = 0;
- int i;
+ int i, ret = 0;
long long min_offset_diff = 0;
int first = 1;

- if (mddev_init_writes_pending(mddev) < 0)
+ if (acct_bioset_init(mddev)) {
+ pr_err("md/raid456:%s: alloc acct bioset failed.\n", mdname(mddev));
return -ENOMEM;
+ }
+
+ if (mddev_init_writes_pending(mddev) < 0) {
+ ret = -ENOMEM;
+ goto exit_acct_set;
+ }

if (mddev->recovery_cp != MaxSector)
pr_notice("md/raid:%s: not clean -- starting background reconstruction\n",
@@ -7482,7 +7489,8 @@ static int raid5_run(struct mddev *mddev
(mddev->bitmap_info.offset || mddev->bitmap_info.file)) {
pr_notice("md/raid:%s: array cannot have both journal and bitmap\n",
mdname(mddev));
- return -EINVAL;
+ ret = -EINVAL;
+ goto exit_acct_set;
}

if (mddev->reshape_position != MaxSector) {
@@ -7507,13 +7515,15 @@ static int raid5_run(struct mddev *mddev
if (journal_dev) {
pr_warn("md/raid:%s: don't support reshape with journal - aborting.\n",
mdname(mddev));
- return -EINVAL;
+ ret = -EINVAL;
+ goto exit_acct_set;
}

if (mddev->new_level != mddev->level) {
pr_warn("md/raid:%s: unsupported reshape required - aborting.\n",
mdname(mddev));
- return -EINVAL;
+ ret = -EINVAL;
+ goto exit_acct_set;
}
old_disks = mddev->raid_disks - mddev->delta_disks;
/* reshape_position must be on a new-stripe boundary, and one
@@ -7529,7 +7539,8 @@ static int raid5_run(struct mddev *mddev
if (sector_div(here_new, chunk_sectors * new_data_disks)) {
pr_warn("md/raid:%s: reshape_position not on a stripe boundary\n",
mdname(mddev));
- return -EINVAL;
+ ret = -EINVAL;
+ goto exit_acct_set;
}
reshape_offset = here_new * chunk_sectors;
/* here_new is the stripe we will write to */
@@ -7551,7 +7562,8 @@ static int raid5_run(struct mddev *mddev
else if (mddev->ro == 0) {
pr_warn("md/raid:%s: in-place reshape must be started in read-only mode - aborting\n",
mdname(mddev));
- return -EINVAL;
+ ret = -EINVAL;
+ goto exit_acct_set;
}
} else if (mddev->reshape_backwards
? (here_new * chunk_sectors + min_offset_diff <=
@@ -7561,7 +7573,8 @@ static int raid5_run(struct mddev *mddev
/* Reading from the same stripe as writing to - bad */
pr_warn("md/raid:%s: reshape_position too early for auto-recovery - aborting.\n",
mdname(mddev));
- return -EINVAL;
+ ret = -EINVAL;
+ goto exit_acct_set;
}
pr_debug("md/raid:%s: reshape will continue\n", mdname(mddev));
/* OK, we should be able to continue; */
@@ -7585,8 +7598,10 @@ static int raid5_run(struct mddev *mddev
else
conf = mddev->private;

- if (IS_ERR(conf))
- return PTR_ERR(conf);
+ if (IS_ERR(conf)) {
+ ret = PTR_ERR(conf);
+ goto exit_acct_set;
+ }

if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
if (!journal_dev) {
@@ -7783,7 +7798,10 @@ abort:
free_conf(conf);
mddev->private = NULL;
pr_warn("md/raid:%s: failed to run raid set.\n", mdname(mddev));
- return -EIO;
+ ret = -EIO;
+exit_acct_set:
+ acct_bioset_exit(mddev);
+ return ret;
}

static void raid5_free(struct mddev *mddev, void *priv)
@@ -7791,6 +7809,7 @@ static void raid5_free(struct mddev *mdd
struct r5conf *conf = priv;

free_conf(conf);
+ acct_bioset_exit(mddev);
mddev->to_remove = &raid5_attrs_group;
}