linux-stable.git/drivers/md/raid5.c, branch linux-4.9.y

drivers:md:fix a potential use-after-free bug

2022-08-25T09:09:31+00:00

[ Upstream commit 104212471b1c1817b311771d817fb692af983173 ]

In line 2884, "raid5_release_stripe(sh);" drops the reference to sh and
may cause sh to be released. However, sh is subsequently used in lines
2886 "if (sh->batch_head && sh != sh->batch_head)". This may result in an
use-after-free bug.

It can be fixed by moving "raid5_release_stripe(sh);" to the bottom of
the function.

Signed-off-by: Wentao_Liang 
Signed-off-by: Song Liu 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

dm raid: fix KASAN warning in raid5_add_disks

2022-07-07T15:30:09+00:00

commit 617b365872a247480e9dcd50a32c8d1806b21861 upstream.

There's a KASAN warning in raid5_add_disk when running the LVM testsuite.
The warning happens in the test
lvconvert-raid-reshape-linear_to_raid6-single-type.sh. We fix the warning
by verifying that rdev->saved_raid_disk is within limits.

Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

md/raid5: fix oops during stripe resizing

2020-11-10T09:23:55+00:00

commit b44c018cdf748b96b676ba09fdbc5b34fc443ada upstream.

KoWei reported crash during raid5 reshape:

[ 1032.252932] Oops: 0002 [#1] SMP PTI
[...]
[ 1032.252943] RIP: 0010:memcpy_erms+0x6/0x10
[...]
[ 1032.252947] RSP: 0018:ffffba1ac0c03b78 EFLAGS: 00010286
[ 1032.252949] RAX: 0000784ac0000000 RBX: ffff91bec3d09740 RCX: 0000000000001000
[ 1032.252951] RDX: 0000000000001000 RSI: ffff91be6781c000 RDI: 0000784ac0000000
[ 1032.252953] RBP: ffffba1ac0c03bd8 R08: 0000000000001000 R09: ffffba1ac0c03bf8
[ 1032.252954] R10: 0000000000000000 R11: 0000000000000000 R12: ffffba1ac0c03bf8
[ 1032.252955] R13: 0000000000001000 R14: 0000000000000000 R15: 0000000000000000
[ 1032.252958] FS:  0000000000000000(0000) GS:ffff91becf500000(0000) knlGS:0000000000000000
[ 1032.252959] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1032.252961] CR2: 0000784ac0000000 CR3: 000000031780a002 CR4: 00000000001606e0
[ 1032.252962] Call Trace:
[ 1032.252969]  ? async_memcpy+0x179/0x1000 [async_memcpy]
[ 1032.252977]  ? raid5_release_stripe+0x8e/0x110 [raid456]
[ 1032.252982]  handle_stripe_expansion+0x15a/0x1f0 [raid456]
[ 1032.252988]  handle_stripe+0x592/0x1270 [raid456]
[ 1032.252993]  handle_active_stripes.isra.0+0x3cb/0x5a0 [raid456]
[ 1032.252999]  raid5d+0x35c/0x550 [raid456]
[ 1032.253002]  ? schedule+0x42/0xb0
[ 1032.253006]  ? schedule_timeout+0x10e/0x160
[ 1032.253011]  md_thread+0x97/0x160
[ 1032.253015]  ? wait_woken+0x80/0x80
[ 1032.253019]  kthread+0x104/0x140
[ 1032.253022]  ? md_start_sync+0x60/0x60
[ 1032.253024]  ? kthread_park+0x90/0x90
[ 1032.253027]  ret_from_fork+0x35/0x40

This is because cache_size_mutex was unlocked too early in resize_stripes,
which races with grow_one_stripe() that grow_one_stripe() allocates a
stripe with wrong pool_size.

Fix this issue by unlocking cache_size_mutex after updating pool_size.

Cc:  # v4.4+
Reported-by: KoWei Sung 
Signed-off-by: Song Liu 
Signed-off-by: Greg Kroah-Hartman

md/raid5: Fix Force reconstruct-write io stuck in degraded raid5

2020-08-21T09:02:08+00:00

commit a1c6ae3d9f3dd6aa5981a332a6f700cf1c25edef upstream.

In degraded raid5, we need to read parity to do reconstruct-write when
data disks fail. However, we can not read parity from
handle_stripe_dirtying() in force reconstruct-write mode.

Reproducible Steps:

1. Create degraded raid5
mdadm -C /dev/md2 --assume-clean -l5 -n3 /dev/sda2 /dev/sdb2 missing
2. Set rmw_level to 0
echo 0 > /sys/block/md2/md/rmw_level
3. IO to raid5

Now some io may be stuck in raid5. We can use handle_stripe_fill() to read
the parity in this situation.

Cc:  # v4.4+
Reviewed-by: Alex Wu 
Reviewed-by: BingJing Chang 
Reviewed-by: Danny Shih 
Signed-off-by: ChangSyun Peng 
Signed-off-by: Song Liu 
Signed-off-by: Greg Kroah-Hartman

md/raid6: Set R5_ReadError when there is read failure on parity disk

2019-10-05T10:30:34+00:00

commit 143f6e733b73051cd22dcb80951c6c929da413ce upstream.

7471fb77ce4d ("md/raid6: Fix anomily when recovering a single device in
RAID6.") avoids rereading P when it can be computed from other members.
However, this misses the chance to re-write the right data to P. This
patch sets R5_ReadError if the re-read fails.

Also, when re-read is skipped, we also missed the chance to reset
rdev->read_errors to 0. It can fail the disk when there are many read
errors on P member disk (other disks don't have read error)

V2: upper layer read request don't read parity/Q data. So there is no
need to consider such situation.

This is Reported-by: kbuild test robot 

Fixes: 7471fb77ce4d ("md/raid6: Fix anomily when recovering a single device in RAID6.")
Cc:  #4.4+
Signed-off-by: Xiao Ni 
Signed-off-by: Song Liu 
Signed-off-by: Greg Kroah-Hartman

md/raid: raid5 preserve the writeback action after the parity check

2019-05-25T16:26:57+00:00

commit b2176a1dfb518d870ee073445d27055fea64dfb8 upstream.

The problem is that any 'uptodate' vs 'disks' check is not precise
in this path. Put a "WARN_ON(!test_bit(R5_UPTODATE, &dev->flags)" on the
device that might try to kick off writes and then skip the action.
Better to prevent the raid driver from taking unexpected action *and* keep
the system alive vs killing the machine with BUG_ON.

Note: fixed warning reported by kbuild test robot 

Signed-off-by: Dan Williams 
Signed-off-by: Nigel Croxon 
Signed-off-by: Song Liu 
Signed-off-by: Greg Kroah-Hartman

Revert "Don't jump to compute_result state from check_result state"

2019-05-25T16:26:57+00:00

commit a25d8c327bb41742dbd59f8c545f59f3b9c39983 upstream.

This reverts commit 4f4fd7c5798bbdd5a03a60f6269cf1177fbd11ef.

Cc: Dan Williams 
Cc: Nigel Croxon 
Cc: Xiao Ni 
Signed-off-by: Song Liu 
Signed-off-by: Greg Kroah-Hartman

Don't jump to compute_result state from check_result state

2019-05-16T17:43:44+00:00

commit 4f4fd7c5798bbdd5a03a60f6269cf1177fbd11ef upstream.

Changing state from check_state_check_result to
check_state_compute_result not only is unsafe but also doesn't
appear to serve a valid purpose.  A raid6 check should only be
pushing out extra writes if doing repair and a mis-match occurs.
The stripe dev management will already try and do repair writes
for failing sectors.

This patch makes the raid6 check_state_check_result handling
work more like raid5's.  If somehow too many failures for a
check, just quit the check operation for the stripe.  When any
checks pass, don't try and use check_state_compute_result for
a purpose it isn't needed for and is unsafe for.  Just mark the
stripe as in sync for passing its parity checks and let the
stripe dev read/write code and the bad blocks list do their
job handling I/O errors.

Repro steps from Xiao:

These are the steps to reproduce this problem:
1. redefined OPT_MEDIUM_ERR_ADDR to 12000 in scsi_debug.c
2. insmod scsi_debug.ko dev_size_mb=11000  max_luns=1 num_tgts=1
3. mdadm --create /dev/md127 --level=6 --raid-devices=5 /dev/sde1 /dev/sde2 /dev/sde3 /dev/sde5 /dev/sde6
sde is the disk created by scsi_debug
4. echo "2" >/sys/module/scsi_debug/parameters/opts
5. raid-check

It panic:
[ 4854.730899] md: data-check of RAID array md127
[ 4854.857455] sd 5:0:0:0: [sdr] tag#80 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 4854.859246] sd 5:0:0:0: [sdr] tag#80 Sense Key : Medium Error [current]
[ 4854.860694] sd 5:0:0:0: [sdr] tag#80 Add. Sense: Unrecovered read error
[ 4854.862207] sd 5:0:0:0: [sdr] tag#80 CDB: Read(10) 28 00 00 00 2d 88 00 04 00 00
[ 4854.864196] print_req_error: critical medium error, dev sdr, sector 11656 flags 0
[ 4854.867409] sd 5:0:0:0: [sdr] tag#100 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 4854.869469] sd 5:0:0:0: [sdr] tag#100 Sense Key : Medium Error [current]
[ 4854.871206] sd 5:0:0:0: [sdr] tag#100 Add. Sense: Unrecovered read error
[ 4854.872858] sd 5:0:0:0: [sdr] tag#100 CDB: Read(10) 28 00 00 00 2e e0 00 00 08 00
[ 4854.874587] print_req_error: critical medium error, dev sdr, sector 12000 flags 4000
[ 4854.876456] sd 5:0:0:0: [sdr] tag#101 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 4854.878552] sd 5:0:0:0: [sdr] tag#101 Sense Key : Medium Error [current]
[ 4854.880278] sd 5:0:0:0: [sdr] tag#101 Add. Sense: Unrecovered read error
[ 4854.881846] sd 5:0:0:0: [sdr] tag#101 CDB: Read(10) 28 00 00 00 2e e8 00 00 08 00
[ 4854.883691] print_req_error: critical medium error, dev sdr, sector 12008 flags 4000
[ 4854.893927] sd 5:0:0:0: [sdr] tag#166 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 4854.896002] sd 5:0:0:0: [sdr] tag#166 Sense Key : Medium Error [current]
[ 4854.897561] sd 5:0:0:0: [sdr] tag#166 Add. Sense: Unrecovered read error
[ 4854.899110] sd 5:0:0:0: [sdr] tag#166 CDB: Read(10) 28 00 00 00 2e e0 00 00 10 00
[ 4854.900989] print_req_error: critical medium error, dev sdr, sector 12000 flags 0
[ 4854.902757] md/raid:md127: read error NOT corrected!! (sector 9952 on sdr1).
[ 4854.904375] md/raid:md127: read error NOT corrected!! (sector 9960 on sdr1).
[ 4854.906201] ------------[ cut here ]------------
[ 4854.907341] kernel BUG at drivers/md/raid5.c:4190!

raid5.c:4190 above is this BUG_ON:

    handle_parity_checks6()
        ...
        BUG_ON(s->uptodate < disks - 1); /* We don't need Q to recover */

Cc:  # v3.16+
OriginalAuthor: David Jeffery 
Cc: Xiao Ni 
Tested-by: David Jeffery 
Signed-off-by: David Jeffy 
Signed-off-by: Nigel Croxon 
Signed-off-by: Song Liu 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

md: Fix failed allocation of md_register_thread

2019-03-23T12:19:53+00:00

commit e406f12dde1a8375d77ea02d91f313fb1a9c6aec upstream.

mddev->sync_thread can be set to NULL on kzalloc failure downstream.
The patch checks for such a scenario and frees allocated resources.

Committer node:

Added similar fix to raid5.c, as suggested by Guoqing.

Cc: stable@vger.kernel.org # v3.16+
Acked-by: Guoqing Jiang 
Signed-off-by: Aditya Pakki 
Signed-off-by: Song Liu 
Signed-off-by: Greg Kroah-Hartman

md/raid5: fix data corruption of replacements after originals dropped

2018-09-19T20:47:12+00:00

[ Upstream commit d63e2fc804c46e50eee825c5d3a7228e07048b47 ]

During raid5 replacement, the stripes can be marked with R5_NeedReplace
flag. Data can be read from being-replaced devices and written to
replacing spares without reading all other devices. (It's 'replace'
mode. s.replacing = 1) If a being-replaced device is dropped, the
replacement progress will be interrupted and resumed with pure recovery
mode. However, existing stripes before being interrupted cannot read
from the dropped device anymore. It prints lots of WARN_ON messages.
And it results in data corruption because existing stripes write
problematic data into its replacement device and update the progress.

\# Erase disks (1MB + 2GB)
dd if=/dev/zero of=/dev/sda bs=1MB count=2049
dd if=/dev/zero of=/dev/sdb bs=1MB count=2049
dd if=/dev/zero of=/dev/sdc bs=1MB count=2049
dd if=/dev/zero of=/dev/sdd bs=1MB count=2049
mdadm -C /dev/md0 -amd -R -l5 -n3 -x0 /dev/sd[abc] -z 2097152
\# Ensure array stores non-zero data
dd if=/root/data_4GB.iso of=/dev/md0 bs=1MB
\# Start replacement
mdadm /dev/md0 -a /dev/sdd
mdadm /dev/md0 --replace /dev/sda

Then, Hot-plug out /dev/sda during recovery, and wait for recovery done.
echo check > /sys/block/md0/md/sync_action
cat /sys/block/md0/md/mismatch_cnt # it will be greater than 0.

Soon after you hot-plug out /dev/sda, you will see many WARN_ON
messages. The replacement recovery will be interrupted shortly. After
the recovery finishes, it will result in data corruption.

Actually, it's just an unhandled case of replacement. In commit
 (md/raid5: fix interaction of 'replace' and 'recovery'.),
if a NeedReplace device is not UPTODATE then that is an error, the
commit just simply print WARN_ON but also mark these corrupted stripes
with R5_WantReplace. (it means it's ready for writes.)

To fix this case, we can leverage 'sync and replace' mode mentioned in
commit <9a3e1101b827> (md/raid5: detect and handle replacements during
recovery.). We can add logics to detect and use 'sync and replace' mode
for these stripes.

Reported-by: Alex Chen 
Reviewed-by: Alex Wu 
Reviewed-by: Chung-Chiang Cheng 
Signed-off-by: BingJing Chang 
Signed-off-by: Shaohua Li 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman