In the Linux kernel, the following vulnerability has been resolved:

md/raid5: Remove unnecessary bio_put() in raid5_read_one_chunk()

When running chunk-sized reads on disks with badblocks duplicate bio
free/puts are observed:

=============================================================================
BUG bio-200 (Not tainted): Object already free
-----------------------------------------------------------------------------
Allocated in mempool_alloc_slab+0x17/0x20 age=3 cpu=2 pid=7504
__slab_alloc.constprop.0+0x5a/0xb0
kmem_cache_alloc+0x31e/0x330
mempool_alloc_slab+0x17/0x20
mempool_alloc+0x100/0x2b0
bio_alloc_bioset+0x181/0x460
do_mpage_readpage+0x776/0xd00
mpage_readahead+0x166/0x320
blkdev_readahead+0x15/0x20
read_pages+0x13f/0x5f0
page_cache_ra_unbounded+0x18d/0x220
force_page_cache_ra+0x181/0x1c0
page_cache_sync_ra+0x65/0xb0
filemap_get_pages+0x1df/0xaf0
filemap_read+0x1e1/0x700
blkdev_read_iter+0x1e5/0x330
vfs_read+0x42a/0x570
Freed in mempool_free_slab+0x17/0x20 age=3 cpu=2 pid=7504
kmem_cache_free+0x46d/0x490
mempool_free_slab+0x17/0x20
mempool_free+0x66/0x190
bio_free+0x78/0x90
bio_put+0x100/0x1a0
raid5_make_request+0x2259/0x2450
md_handle_request+0x402/0x600
md_submit_bio+0xd9/0x120
__submit_bio+0x11f/0x1b0
submit_bio_noacct_nocheck+0x204/0x480
submit_bio_noacct+0x32e/0xc70
submit_bio+0x98/0x1a0
mpage_readahead+0x250/0x320
blkdev_readahead+0x15/0x20
read_pages+0x13f/0x5f0
page_cache_ra_unbounded+0x18d/0x220
Slab 0xffffea000481b600 objects=21 used=0 fp=0xffff8881206d8940 flags=0x17ffffc0010201(locked|slab|head|node=0|zone=2|lastcpupid=0x1fffff)
CPU: 0 PID: 34525 Comm: kworker/u24:2 Not tainted 6.0.0-rc2-localyes-265166-gf11c5343fa3f #143
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Workqueue: raid5wq raid5_do_work
Call Trace:
<TASK>
dump_stack_lvl+0x5a/0x78
dump_stack+0x10/0x16
print_trailer+0x158/0x165
object_err+0x35/0x50
free_debug_processing.cold+0xb7/0xbe
__slab_free+0x1ae/0x330
kmem_cache_free+0x46d/0x490
mempool_free_slab+0x17/0x20
mempool_free+0x66/0x190
bio_free+0x78/0x90
bio_put+0x100/0x1a0
mpage_end_io+0x36/0x150
bio_endio+0x2fd/0x360
md_end_io_acct+0x7e/0x90
bio_endio+0x2fd/0x360
handle_failed_stripe+0x960/0xb80
handle_stripe+0x1348/0x3760
handle_active_stripes.constprop.0+0x72a/0xaf0
raid5_do_work+0x177/0x330
process_one_work+0x616/0xb20
worker_thread+0x2bd/0x6f0
kthread+0x179/0x1b0
ret_from_fork+0x22/0x30
</TASK>

The double free is caused by an unnecessary bio_put() in the
if(is_badblock(...)) error path in raid5_read_one_chunk().

The error path was moved ahead of bio_alloc_clone() in c82aa1b76787c
("md/raid5: move checking badblock before clone bio in
raid5_read_one_chunk"). The previous code checked and freed align_bio
which required a bio_put. After the move that is no longer needed as
raid_bio is returned to the control of the common io path which
performs its own endio resulting in a double free on bad device blocks.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 25 Dec 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low


Wed, 24 Dec 2025 13:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: md/raid5: Remove unnecessary bio_put() in raid5_read_one_chunk() When running chunk-sized reads on disks with badblocks duplicate bio free/puts are observed: ============================================================================= BUG bio-200 (Not tainted): Object already free ----------------------------------------------------------------------------- Allocated in mempool_alloc_slab+0x17/0x20 age=3 cpu=2 pid=7504 __slab_alloc.constprop.0+0x5a/0xb0 kmem_cache_alloc+0x31e/0x330 mempool_alloc_slab+0x17/0x20 mempool_alloc+0x100/0x2b0 bio_alloc_bioset+0x181/0x460 do_mpage_readpage+0x776/0xd00 mpage_readahead+0x166/0x320 blkdev_readahead+0x15/0x20 read_pages+0x13f/0x5f0 page_cache_ra_unbounded+0x18d/0x220 force_page_cache_ra+0x181/0x1c0 page_cache_sync_ra+0x65/0xb0 filemap_get_pages+0x1df/0xaf0 filemap_read+0x1e1/0x700 blkdev_read_iter+0x1e5/0x330 vfs_read+0x42a/0x570 Freed in mempool_free_slab+0x17/0x20 age=3 cpu=2 pid=7504 kmem_cache_free+0x46d/0x490 mempool_free_slab+0x17/0x20 mempool_free+0x66/0x190 bio_free+0x78/0x90 bio_put+0x100/0x1a0 raid5_make_request+0x2259/0x2450 md_handle_request+0x402/0x600 md_submit_bio+0xd9/0x120 __submit_bio+0x11f/0x1b0 submit_bio_noacct_nocheck+0x204/0x480 submit_bio_noacct+0x32e/0xc70 submit_bio+0x98/0x1a0 mpage_readahead+0x250/0x320 blkdev_readahead+0x15/0x20 read_pages+0x13f/0x5f0 page_cache_ra_unbounded+0x18d/0x220 Slab 0xffffea000481b600 objects=21 used=0 fp=0xffff8881206d8940 flags=0x17ffffc0010201(locked|slab|head|node=0|zone=2|lastcpupid=0x1fffff) CPU: 0 PID: 34525 Comm: kworker/u24:2 Not tainted 6.0.0-rc2-localyes-265166-gf11c5343fa3f #143 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: raid5wq raid5_do_work Call Trace: <TASK> dump_stack_lvl+0x5a/0x78 dump_stack+0x10/0x16 print_trailer+0x158/0x165 object_err+0x35/0x50 free_debug_processing.cold+0xb7/0xbe __slab_free+0x1ae/0x330 kmem_cache_free+0x46d/0x490 mempool_free_slab+0x17/0x20 mempool_free+0x66/0x190 bio_free+0x78/0x90 bio_put+0x100/0x1a0 mpage_end_io+0x36/0x150 bio_endio+0x2fd/0x360 md_end_io_acct+0x7e/0x90 bio_endio+0x2fd/0x360 handle_failed_stripe+0x960/0xb80 handle_stripe+0x1348/0x3760 handle_active_stripes.constprop.0+0x72a/0xaf0 raid5_do_work+0x177/0x330 process_one_work+0x616/0xb20 worker_thread+0x2bd/0x6f0 kthread+0x179/0x1b0 ret_from_fork+0x22/0x30 </TASK> The double free is caused by an unnecessary bio_put() in the if(is_badblock(...)) error path in raid5_read_one_chunk(). The error path was moved ahead of bio_alloc_clone() in c82aa1b76787c ("md/raid5: move checking badblock before clone bio in raid5_read_one_chunk"). The previous code checked and freed align_bio which required a bio_put. After the move that is no longer needed as raid_bio is returned to the control of the common io path which performs its own endio resulting in a double free on bad device blocks.
Title md/raid5: Remove unnecessary bio_put() in raid5_read_one_chunk()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-12-24T13:05:46.881Z

Reserved: 2025-12-24T13:02:21.544Z

Link: CVE-2022-50752

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-12-24T13:16:01.930

Modified: 2025-12-29T15:58:34.503

Link: CVE-2022-50752

cve-icon Redhat

Severity : Low

Publid Date: 2025-12-24T00:00:00Z

Links: CVE-2022-50752 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.