From: Xiao Ni xni@redhat.com
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@vger.kernel.org Acked-by: Guoqing Jiang guoqing.jiang@linux.dev Signed-off-by: Xiao Ni xni@redhat.com Signed-off-by: Song Liu song@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -5872,13 +5872,6 @@ 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); @@ -6055,9 +6048,6 @@ 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); @@ -8590,6 +8580,23 @@ 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) { @@ -7786,7 +7801,10 @@ 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) @@ -7794,6 +7812,7 @@ static void raid5_free(struct mddev *mdd struct r5conf *conf = priv;
free_conf(conf); + acct_bioset_exit(mddev); mddev->to_remove = &raid5_attrs_group; }