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CVE Record

CVE-2022-48649: mm/slab_common: fix possible double free of kmem_cache

In the Linux kernel, the following vulnerability has been resolved: mm/slab_common: fix possible double free of kmem_cache When doing slub_debug test, kfence's 'test_memcache_typesafe_by_rcu' kunit test case cause a use-after-free error: BUG: KASAN: use-after-free in kobject_del+0x14/0x30 Read of size 8 at addr ffff888007679090 by task kunit_try_catch/261 CPU: 1 PID: 261 Comm: kunit_try_catch Tainted: G B N 6.0.0-rc5-next-20220916 #17 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x34/0x48 print_address_description.constprop.0+0x87/0x2a5 print_report+0x103/0x1ed kasan_report+0xb7/0x140 kobject_del+0x14/0x30 kmem_cache_destroy+0x130/0x170 test_exit+0x1a/0x30 kunit_try_run_case+0xad/0xc0 kunit_generic_run_threadfn_adapter+0x26/0x50 kthread+0x17b/0x1b0 </TASK> The cause is inside kmem_cache_destroy(): kmem_cache_destroy acquire lock/mutex shutdown_cache schedule_work(kmem_cache_release) (if RCU flag set) release lock/mutex kmem_cache_release (if RCU flag not set) In some certain timing, the scheduled work could be run before the next RCU flag checking, which can then get a wrong value and lead to double kmem_cache_release(). Fix it by caching the RCU flag inside protected area, just like 'refcnt'

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel memory-management bug that could cause a kmem_cache object to be released twice under specific timing. The public description ties discovery to kernel debug/KUnit testing, not real-world compromise. Business urgency is unclear because severity, CVSS, affected version ranges, and practical attack path are not provided.

Executive priority

Treat as a kernel maintenance item unless vendor guidance raises severity. Patch through the normal operating-system update process, with extra attention to custom kernels because the source bundle lacks full version mapping.

Technical view

kmem_cache_destroy could schedule kmem_cache_release for RCU caches, then later re-check an RCU flag after work already ran. That race could use a stale or wrong value and trigger a double release/use-after-free. The fix caches the RCU flag while protected, matching the handling of the reference count.

Likely exposure

Exposure is limited to Linux kernels containing the vulnerable mm/slab_common behavior. The bundle lists Linux and stable commit references but does not provide complete affected version ranges, distributions, configurations, or package names.

Exploitation context

The source bundle does not show active exploitation, and KEV is false. Evidence describes a KASAN use-after-free during slub_debug with a KFENCE KUnit test. No public exploitability, privilege requirement, or attacker-controlled trigger is established here.

Researcher notes

The core issue is a race in kmem_cache_destroy around deferred RCU cache release. Available evidence is strong for the bug and fix mechanism but weak for external exploitability, affected ranges, and operational impact. Do not claim exploitation without additional vendor or KEV evidence.

Mitigation direction

  • Apply vendor kernel updates that include the referenced stable fixes.
  • Check Linux distribution advisories for CVE-2022-48649 package status.
  • Prioritize custom or self-built kernels for commit-level review.
  • Avoid assuming mitigation beyond vendor kernel guidance.
  • Track this CVE in normal kernel patch management workflows.

Validation and detection

  • Record the running kernel version on Linux assets.
  • Review kernel changelogs for the two stable commit IDs.
  • Confirm scanners map CVE-2022-48649 to installed kernel builds.
  • Check custom kernel source trees for the mm/slab_common fix.
  • Document unresolved version-mapping gaps for risk acceptance.
Prepared
Confidence
medium
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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CVE-2022-48649 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
2ADP providers
3Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container
CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux357321557920c805de2b14832002465c320eea4f, 0495e337b7039191dfce6e03f5f830454b1fae6bunaffected
LinuxLinux5.19.8unaffected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.