linux-stable.git/drivers/md, branch linux-4.14.y

dm-integrity: don't modify bio's immutable bio_vec in integrity_metadata()

2024-01-08T10:25:04+00:00

commit b86f4b790c998afdbc88fe1aa55cfe89c4068726 upstream.

__bio_for_each_segment assumes that the first struct bio_vec argument
doesn't change - it calls "bio_advance_iter_single((bio), &(iter),
(bvl).bv_len)" to advance the iterator. Unfortunately, the dm-integrity
code changes the bio_vec with "bv.bv_len -= pos". When this code path
is taken, the iterator would be out of sync and dm-integrity would
report errors. This happens if the machine is out of memory and
"kmalloc" fails.

Fix this bug by making a copy of "bv" and changing the copy instead.

Fixes: 7eada909bfd7 ("dm: add integrity target")
Cc: stable@vger.kernel.org	# v4.12+
Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

bcache: add code comments for bch_btree_node_get() and __bch_btree_node_alloc()

2023-12-20T14:32:35+00:00

[ Upstream commit 31f5b956a197d4ec25c8a07cb3a2ab69d0c0b82f ]

This patch adds code comments to bch_btree_node_get() and
__bch_btree_node_alloc() that NULL pointer will not be returned and it
is unnecessary to check NULL pointer by the callers of these routines.

Signed-off-by: Coly Li 
Link: https://lore.kernel.org/r/20231120052503.6122-10-colyli@suse.de
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

dm verity: don't perform FEC for failed readahead IO

2023-12-08T07:42:00+00:00

commit 0193e3966ceeeef69e235975918b287ab093082b upstream.

We found an issue under Android OTA scenario that many BIOs have to do
FEC where the data under dm-verity is 100% complete and no corruption.

Android OTA has many dm-block layers, from upper to lower:
dm-verity
dm-snapshot
dm-origin & dm-cow
dm-linear
ufs

DM tables have to change 2 times during Android OTA merging process.
When doing table change, the dm-snapshot will be suspended for a while.
During this interval, many readahead IOs are submitted to dm_verity
from filesystem. Then the kverity works are busy doing FEC process
which cost too much time to finish dm-verity IO. This causes needless
delay which feels like system is hung.

After adding debugging it was found that each readahead IO needed
around 10s to finish when this situation occurred. This is due to IO
amplification:

dm-snapshot suspend
erofs_readahead     // 300+ io is submitted
	dm_submit_bio (dm_verity)
		dm_submit_bio (dm_snapshot)
		bio return EIO
		bio got nothing, it's empty
	verity_end_io
	verity_verify_io
	forloop range(0, io->n_blocks)    // each io->nblocks ~= 20
		verity_fec_decode
		fec_decode_rsb
		fec_read_bufs
		forloop range(0, v->fec->rsn) // v->fec->rsn = 253
			new_read
			submit_bio (dm_snapshot)
		end loop
	end loop
dm-snapshot resume

Readahead BIOs get nothing while dm-snapshot is suspended, so all of
them will cause verity's FEC.
Each readahead BIO needs to verify ~20 (io->nblocks) blocks.
Each block needs to do FEC, and every block needs to do 253
(v->fec->rsn) reads.
So during the suspend interval(~200ms), 300 readahead BIOs trigger
~1518000 (300*20*253) IOs to dm-snapshot.

As readahead IO is not required by userspace, and to fix this issue,
it is best to pass readahead errors to upper layer to handle it.

Cc: stable@vger.kernel.org
Fixes: a739ff3f543a ("dm verity: add support for forward error correction")
Signed-off-by: Wu Bo 
Reviewed-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm-verity: align struct dm_verity_fec_io properly

2023-12-08T07:42:00+00:00

commit 38bc1ab135db87577695816b190e7d6d8ec75879 upstream.

dm_verity_fec_io is placed after the end of two hash digests. If the hash
digest has unaligned length, struct dm_verity_fec_io could be unaligned.

This commit fixes the placement of struct dm_verity_fec_io, so that it's
aligned.

Signed-off-by: Mikulas Patocka 
Cc: stable@vger.kernel.org
Fixes: a739ff3f543a ("dm verity: add support for forward error correction")
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

bcache: prevent potential division by zero error

2023-12-08T07:41:59+00:00

commit 2c7f497ac274a14330208b18f6f734000868ebf9 upstream.

In SHOW(), the variable 'n' is of type 'size_t.' While there is a
conditional check to verify that 'n' is not equal to zero before
executing the 'do_div' macro, concerns arise regarding potential
division by zero error in 64-bit environments.

The concern arises when 'n' is 64 bits in size, greater than zero, and
the lower 32 bits of it are zeros. In such cases, the conditional check
passes because 'n' is non-zero, but the 'do_div' macro casts 'n' to
'uint32_t,' effectively truncating it to its lower 32 bits.
Consequently, the 'n' value becomes zero.

To fix this potential division by zero error and ensure precise
division handling, this commit replaces the 'do_div' macro with
div64_u64(). div64_u64() is designed to work with 64-bit operands,
guaranteeing that division is performed correctly.

This change enhances the robustness of the code, ensuring that division
operations yield accurate results in all scenarios, eliminating the
possibility of division by zero, and improving compatibility across
different 64-bit environments.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Rand Deeb 
Cc:  
Signed-off-by: Coly Li 
Link: https://lore.kernel.org/r/20231120052503.6122-5-colyli@suse.de
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

bcache: check return value from btree_node_alloc_replacement()

2023-12-08T07:41:59+00:00

commit 777967e7e9f6f5f3e153abffb562bffaf4430d26 upstream.

In btree_gc_rewrite_node(), pointer 'n' is not checked after it returns
from btree_gc_rewrite_node(). There is potential possibility that 'n' is
a non NULL ERR_PTR(), referencing such error code is not permitted in
following code. Therefore a return value checking is necessary after 'n'
is back from btree_node_alloc_replacement().

Signed-off-by: Coly Li 
Reported-by: Dan Carpenter 
Cc:  
Link: https://lore.kernel.org/r/20231120052503.6122-3-colyli@suse.de
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

md/raid1: fix error: ISO C90 forbids mixed declarations

2023-09-23T08:47:05+00:00

[ Upstream commit df203da47f4428bc286fc99318936416253a321c ]

There is a compile error when this commit is added:
md: raid1: fix potential OOB in raid1_remove_disk()

drivers/md/raid1.c: In function 'raid1_remove_disk':
drivers/md/raid1.c:1844:9: error: ISO C90 forbids mixed declarations
and code [-Werror=declaration-after-statement]
1844 |         struct raid1_info *p = conf->mirrors + number;
     |         ^~~~~~

That's because the new code was inserted before the struct.
The change is move the struct command above this commit.

Fixes: 8b0472b50bcf ("md: raid1: fix potential OOB in raid1_remove_disk()")
Signed-off-by: Nigel Croxon 
Signed-off-by: Song Liu 
Link: https://lore.kernel.org/r/46d929d0-2aab-4cf2-b2bf-338963e8ba5a@redhat.com
Signed-off-by: Sasha Levin

md: raid1: fix potential OOB in raid1_remove_disk()

2023-09-23T08:47:04+00:00

[ Upstream commit 8b0472b50bcf0f19a5119b00a53b63579c8e1e4d ]

If rddev->raid_disk is greater than mddev->raid_disks, there will be
an out-of-bounds in raid1_remove_disk(). We have already found
similar reports as follows:

1) commit d17f744e883b ("md-raid10: fix KASAN warning")
2) commit 1ebc2cec0b7d ("dm raid: fix KASAN warning in raid5_remove_disk")

Fix this bug by checking whether the "number" variable is
valid.

Signed-off-by: Zhang Shurong 
Reviewed-by: Yu Kuai 
Link: https://lore.kernel.org/r/tencent_0D24426FAC6A21B69AC0C03CE4143A508F09@qq.com
Signed-off-by: Song Liu 
Signed-off-by: Sasha Levin

dm cache policy smq: ensure IO doesn't prevent cleaner policy progress

2023-08-11T09:33:53+00:00

commit 1e4ab7b4c881cf26c1c72b3f56519e03475486fb upstream.

When using the cleaner policy to decommission the cache, there is
never any writeback started from the cache as it is constantly delayed
due to normal I/O keeping the device busy. Meaning @idle=false was
always being passed to clean_target_met()

Fix this by adding a specific 'cleaner' flag that is set when the
cleaner policy is configured. This flag serves to always allow the
cleaner's writeback work to be queued until the cache is
decommissioned (even if the cache isn't idle).

Reported-by: David Jeffery 
Fixes: b29d4986d0da ("dm cache: significant rework to leverage dm-bio-prison-v2")
Cc: stable@vger.kernel.org
Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm raid: fix missing reconfig_mutex unlock in raid_ctr() error paths

2023-08-11T09:33:51+00:00

[ Upstream commit bae3028799dc4f1109acc4df37c8ff06f2d8f1a0 ]

In the error paths 'bad_stripe_cache' and 'bad_check_reshape',
'reconfig_mutex' is still held after raid_ctr() returns.

Fixes: 9dbd1aa3a81c ("dm raid: add reshaping support to the target")
Signed-off-by: Yu Kuai 
Signed-off-by: Mike Snitzer 
Signed-off-by: Sasha Levin