CVE-2022-50752
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:
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.
Detalles técnicos trazas, registros y código del informe original
=============================================================================
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>CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.20%
- Percentil entre todas las CVEs puntuadas: 8
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1068Exploitation for Privilege Escalationprivilege escalation60 %
Inferido por reglas deterministas a partir del vector CVSS y la CWE. Solo orientativo.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2022-50752",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1.8
}
]
},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "c82aa1b76787c34fd02374e519b6f52cdeb2f54b",
"lessThan": "7a37c58ee72e1fadd22c4ee990cb74c2ca2280e7",
"versionType": "git"
},
{
"status": "affected",
"version": "c82aa1b76787c34fd02374e519b6f52cdeb2f54b",
"lessThan": "c0fd5d4d8fd7b1a50306d7a23c720cf808f41fdf",
"versionType": "git"
},
{
"status": "affected",
"version": "c82aa1b76787c34fd02374e519b6f52cdeb2f54b",
"lessThan": "21a9c7354aa59e97e26ece5f0a609c8bfa43020d",
"versionType": "git"
},
{
"status": "affected",
"version": "c82aa1b76787c34fd02374e519b6f52cdeb2f54b",
"lessThan": "c66a6f41e09ad386fd2cce22b9cded837bbbc704",
"versionType": "git"
}
],
"programFiles": [
"drivers/md/raid5.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.14"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.14",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.15.75",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "5.19.17",
"versionType": "semver",
"lessThanOrEqual": "5.19.*"
},
{
"status": "unaffected",
"version": "6.0.3",
"versionType": "semver",
"lessThanOrEqual": "6.0.*"
},
{
"status": "unaffected",
"version": "6.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/md/raid5.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2025-12-24T13:16:01.930",
"references": [
{
"url": "https://git.kernel.org/stable/c/21a9c7354aa59e97e26ece5f0a609c8bfa43020d",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/7a37c58ee72e1fadd22c4ee990cb74c2ca2280e7",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/c0fd5d4d8fd7b1a50306d7a23c720cf808f41fdf",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/c66a6f41e09ad386fd2cce22b9cded837bbbc704",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Deferred",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmd/raid5: Remove unnecessary bio_put() in raid5_read_one_chunk()\n\nWhen running chunk-sized reads on disks with badblocks duplicate bio\nfree/puts are observed:\n\n =============================================================================\n BUG bio-200 (Not tainted): Object already free\n -----------------------------------------------------------------------------\n Allocated in mempool_alloc_slab+0x17/0x20 age=3 cpu=2 pid=7504\n __slab_alloc.constprop.0+0x5a/0xb0\n kmem_cache_alloc+0x31e/0x330\n mempool_alloc_slab+0x17/0x20\n mempool_alloc+0x100/0x2b0\n bio_alloc_bioset+0x181/0x460\n do_mpage_readpage+0x776/0xd00\n mpage_readahead+0x166/0x320\n blkdev_readahead+0x15/0x20\n read_pages+0x13f/0x5f0\n page_cache_ra_unbounded+0x18d/0x220\n force_page_cache_ra+0x181/0x1c0\n page_cache_sync_ra+0x65/0xb0\n filemap_get_pages+0x1df/0xaf0\n filemap_read+0x1e1/0x700\n blkdev_read_iter+0x1e5/0x330\n vfs_read+0x42a/0x570\n Freed in mempool_free_slab+0x17/0x20 age=3 cpu=2 pid=7504\n kmem_cache_free+0x46d/0x490\n mempool_free_slab+0x17/0x20\n mempool_free+0x66/0x190\n bio_free+0x78/0x90\n bio_put+0x100/0x1a0\n raid5_make_request+0x2259/0x2450\n md_handle_request+0x402/0x600\n md_submit_bio+0xd9/0x120\n __submit_bio+0x11f/0x1b0\n submit_bio_noacct_nocheck+0x204/0x480\n submit_bio_noacct+0x32e/0xc70\n submit_bio+0x98/0x1a0\n mpage_readahead+0x250/0x320\n blkdev_readahead+0x15/0x20\n read_pages+0x13f/0x5f0\n page_cache_ra_unbounded+0x18d/0x220\n Slab 0xffffea000481b600 objects=21 used=0 fp=0xffff8881206d8940 flags=0x17ffffc0010201(locked|slab|head|node=0|zone=2|lastcpupid=0x1fffff)\n CPU: 0 PID: 34525 Comm: kworker/u24:2 Not tainted 6.0.0-rc2-localyes-265166-gf11c5343fa3f #143\n Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014\n Workqueue: raid5wq raid5_do_work\n Call Trace:\n <TASK>\n dump_stack_lvl+0x5a/0x78\n dump_stack+0x10/0x16\n print_trailer+0x158/0x165\n object_err+0x35/0x50\n free_debug_processing.cold+0xb7/0xbe\n __slab_free+0x1ae/0x330\n kmem_cache_free+0x46d/0x490\n mempool_free_slab+0x17/0x20\n mempool_free+0x66/0x190\n bio_free+0x78/0x90\n bio_put+0x100/0x1a0\n mpage_end_io+0x36/0x150\n bio_endio+0x2fd/0x360\n md_end_io_acct+0x7e/0x90\n bio_endio+0x2fd/0x360\n handle_failed_stripe+0x960/0xb80\n handle_stripe+0x1348/0x3760\n handle_active_stripes.constprop.0+0x72a/0xaf0\n raid5_do_work+0x177/0x330\n process_one_work+0x616/0xb20\n worker_thread+0x2bd/0x6f0\n kthread+0x179/0x1b0\n ret_from_fork+0x22/0x30\n </TASK>\n\nThe double free is caused by an unnecessary bio_put() in the\nif(is_badblock(...)) error path in raid5_read_one_chunk().\n\nThe error path was moved ahead of bio_alloc_clone() in c82aa1b76787c\n(\"md/raid5: move checking badblock before clone bio in\nraid5_read_one_chunk\"). The previous code checked and freed align_bio\nwhich required a bio_put. After the move that is no longer needed as\nraid_bio is returned to the control of the common io path which\nperforms its own endio resulting in a double free on bad device blocks."
}
],
"lastModified": "2026-08-04T10:18:23.233",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}