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Full vulnerability report · 2025
CVE-2022-50323High confidence

net: do not sense pfmemalloc status in skb_append_pagefrags()

Linux · Linux

5.5MediumCVSS 3.1
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

9 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Ubuntu releaseSource packageVendor stateFixed versionEvidence
Ubuntu 24.04 LTSnoble · standard archivelinux-azure-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 9 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-gcp-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 9 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-hwe-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 9 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-intelAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 9 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-lowlatency-hwe-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 9 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-oem-6.11Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 9 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-raspi-realtimeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 9 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-realtimeAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 9 Sept 2026
Ubuntu 24.04 LTSnoble · standard archivelinux-riscvAffected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition.Not published in this feedCanonical record ↗Source updated 9 Sept 2026
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2022-55532

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

In the Linux kernel, the following vulnerability has been resolved: net: do not sense pfmemalloc status in skb_append_pagefrags() skb_append_pagefrags() is used by af_unix and udp sendpage() implementation so far. In commit 326140063946 ("tcp: TX zerocopy should not sense pfmemalloc status") we explained why we should not sense pfmemalloc status for pages owned by user space. We should also use skb_fill_page_desc_noacc() in skb_append_pagefrags() to avoid following KCSAN report: BUG: KCSAN: data-race in lru_add_fn / skb_append_pagefrags write to 0xffffea00058fc1c8 of 8 bytes by task 17319 on cpu 0: __list_add include/linux/list.h:73 [inline] list_add include/linux/list.h:88 [inline] lruvec_add_folio include/linux/mm_inline.h:323 [inline] lru_add_fn+0x327/0x410 mm/swap.c:228 folio_batch_move_lru+0x1e1/0x2a0 mm/swap.c:246 lru_add_drain_cpu+0x73/0x250 mm/swap.c:669 lru_add_drain+0x21/0x60 mm/swap.c:773 free_pages_and_swap_cache+0x16/0x70 mm/swap_state.c:311 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline] tlb_flush_mmu_free mm/mmu_gather.c:256 [inline] tlb_flush_mmu+0x5b2/0x640 mm/mmu_gather.c:263 tlb_finish_mmu+0x86/0x100 mm/mmu_gather.c:363 exit_mmap+0x190/0x4d0 mm/mmap.c:3098 __mmput+0x27/0x1b0 kernel/fork.c:1185 mmput+0x3d/0x50 kernel/fork.c:1207 copy_process+0x19fc/0x2100 kernel/fork.c:2518 kernel_clone+0x166/0x550 kernel/fork.c:2671 __do_sys_clone kernel/fork.c:2812 [inline] __se_sys_clone kernel/fork.c:2796 [inline] __x64_sys_clone+0xc3/0xf0 kernel/fork.c:2796 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffffea00058fc1c8 of 8 bytes by task 17325 on cpu 1: page_is_pfmemalloc include/linux/mm.h:1817 [inline] __skb_fill_page_desc include/linux/skbuff.h:2432 [inline] skb_fill_page_desc include/linux/skbuff.h:2453 [inline] skb_append_pagefrags+0x210/0x600 net/core/skbuff.c:3974 unix_stream_sendpage+0x45e/0x990 net/unix/af_unix.c:2338 kernel_sendpage+0x184/0x300 net/socket.c:3561 sock_sendpage+0x5a/0x70 net/socket.c:1054 pipe_to_sendpage+0x128/0x160 fs/splice.c:361 splice_from_pipe_feed fs/splice.c:415 [inline] __splice_from_pipe+0x222/0x4d0 fs/splice.c:559 splice_from_pipe fs/splice.c:594 [inline] generic_splice_sendpage+0x89/0xc0 fs/splice.c:743 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:931 splice_direct_to_actor+0x305/0x620 fs/splice.c:886 do_splice_direct+0xfb/0x180 fs/splice.c:974 do_sendfile+0x3bf/0x910 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x0000000000000000 -> 0xffffea00058fc188 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 17325 Comm: syz-executor.0 Not tainted 6.1.0-rc1-syzkaller-00158-g440b7895c990-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022

What

In the Linux kernel, the following vulnerability has been resolved: net: do not sense pfmemalloc status in skb_append_pagefrags() skb_append_pagefrags() is used by af_unix and udp sendpage() implementation so far. In commit 326140063946 ("tcp: TX zerocopy should not sense pfmemalloc status") we explained why we should not sense pfmemalloc status for pages owned by user space. We should also use skb_fill_page_desc_noacc() in skb_append_pagefrags() to avoid following KCSAN report: BUG: KCSAN: data-race in lru_add_fn / skb_append_pagefrags write to 0xffffea00058fc1c8 of 8 bytes by task 17319 on cpu 0: __list_add include/linux/list.h:73 [inline] list_add include/linux/list.h:88 [inline] lruvec_add_folio include/linux/mm_inline.h:323 [inline] lru_add_fn+0x327/0x410 mm/swap.c:228 folio_batch_move_lru+0x1e1/0x2a0 mm/swap.c:246 lru_add_drain_cpu+0x73/0x250 mm/swap.c:669 lru_add_drain+0x21/0x60 mm/swap.c:773 free_pages_and_swap_cache+0x16/0x70 mm/swap_state.c:311 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline] tlb_flush_mmu_free mm/mmu_gather.c:256 [inline] tlb_flush_mmu+0x5b2/0x640 mm/mmu_gather.c:263 tlb_finish_mmu+0x86/0x100 mm/mmu_gather.c:363 exit_mmap+0x190/0x4d0 mm/mmap.c:3098 __mmput+0x27/0x1b0 kernel/fork.c:1185 mmput+0x3d/0x50 kernel/fork.c:1207 copy_process+0x19fc/0x2100 kernel/fork.c:2518 kernel_clone+0x166/0x550 kernel/fork.c:2671 __do_sys_clone kernel/fork.c:2812 [inline] __se_sys_clone kernel/fork.c:2796 [inline] __x64_sys_clone+0xc3/0xf0 kernel/fork.c:2796 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffffea00058fc1c8 of 8 bytes by task 17325 on cpu 1: page_is_pfmemalloc include/linux/mm.h:1817 [inline] __skb_fill_page_desc include/linux/skbuff.h:2432 [inline] skb_fill_page_desc include/linux/skbuff.h:2453 [inline] skb_append_pagefrags+0x210/0x600 net/core/skbuff.c:3974 unix_stream_sendpage+0x45e/0x990 net/unix/af_unix.c:2338 kernel_sendpage+0x184/0x300 net/socket.c:3561 sock_sendpage+0x5a/0x70 net/socket.c:1054 pipe_to_sendpage+0x128/0x160 fs/splice.c:361 splice_from_pipe_feed fs/splice.c:415 [inline] __splice_from_pipe+0x222/0x4d0 fs/splice.c:559 splice_from_pipe fs/splice.c:594 [inline] generic_splice_sendpage+0x89/0xc0 fs/splice.c:743 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:931 splice_direct_to_actor+0x305/0x620 fs/splice.c:886 do_splice_direct+0xfb/0x180 fs/splice.c:974 do_sendfile+0x3bf/0x910 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x0000000000000000 -> 0xffffea00058fc188 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 17325 Comm: syz-executor.0 Not tainted 6.1.0-rc1-syzkaller-00158-g440b7895c990-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022

Why

The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

In the Linux kernel, the following vulnerability has been resolved: net: do not sense pfmemalloc status in skb_append_pagefrags() skb_append_pagefrags() is used by af_unix and udp sendpage() implementation so far. In commit 326140063946 ("tcp: TX zerocopy should not sense pfmemalloc status") we explained why we should not sense pfmemalloc status for pages owned by user space. We should also use skb_fill_page_desc_noacc() in skb_append_pagefrags() to avoid following KCSAN report: BUG: KCSAN: data-race in lru_add_fn / skb_append_pagefrags write to 0xffffea00058fc1c8 of 8 bytes by task 17319 on cpu 0: __list_add include/linux/list.h:73 [inline] list_add include/linux/list.h:88 [inline] lruvec_add_folio include/linux/mm_inline.h:323 [inline] lru_add_fn+0x327/0x410 mm/swap.c:228 folio_batch_move_lru+0x1e1/0x2a0 mm/swap.c:246 lru_add_drain_cpu+0x73/0x250 mm/swap.c:669 lru_add_drain+0x21/0x60 mm/swap.c:773 free_pages_and_swap_cache+0x16/0x70 mm/swap_state.c:311 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline] tlb_flush_mmu_free mm/mmu_gather.c:256 [inline] tlb_flush_mmu+0x5b2/0x640 mm/mmu_gather.c:263 tlb_finish_mmu+0x86/0x100 mm/mmu_gather.c:363 exit_mmap+0x190/0x4d0 mm/mmap.c:3098 __mmput+0x27/0x1b0 kernel/fork.c:1185 mmput+0x3d/0x50 kernel/fork.c:1207 copy_process+0x19fc/0x2100 kernel/fork.c:2518 kernel_clone+0x166/0x550 kernel/fork.c:2671 __do_sys_clone kernel/fork.c:2812 [inline] __se_sys_clone kernel/fork.c:2796 [inline] __x64_sys_clone+0xc3/0xf0 kernel/fork.c:2796 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffffea00058fc1c8 of 8 bytes by task 17325 on cpu 1: page_is_pfmemalloc include/linux/mm.h:1817 [inline] __skb_fill_page_desc include/linux/skbuff.h:2432 [inline] skb_fill_page_desc include/linux/skbuff.h:2453 [inline] skb_append_pagefrags+0x210/0x600 net/core/skbuff.c:3974 unix_stream_sendpage+0x45e/0x990 net/unix/af_unix.c:2338 kernel_sendpage+0x184/0x300 net/socket.c:3561 sock_sendpage+0x5a/0x70 net/socket.c:1054 pipe_to_sendpage+0x128/0x160 fs/splice.c:361 splice_from_pipe_feed fs/splice.c:415 [inline] __splice_from_pipe+0x222/0x4d0 fs/splice.c:559 splice_from_pipe fs/splice.c:594 [inline] generic_splice_sendpage+0x89/0xc0 fs/splice.c:743 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:931 splice_direct_to_actor+0x305/0x620 fs/splice.c:886 do_splice_direct+0xfb/0x180 fs/splice.c:974 do_sendfile+0x3bf/0x910 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x0000000000000000 -> 0xffffea00058fc188 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 17325 Comm: syz-executor.0 Not tainted 6.1.0-rc1-syzkaller-00158-g440b7895c990-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022

Why

The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
local access → vulnerable operation → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration.
CWE not yet assigned
CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-W-2025-2053Linux Kernel: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen oder nicht näher beschriebene Auswirkungen zu erzielen.

Official advisory
CERT-FR · French · CERTFR-2025-AVI-0895Multiples vulnérabilités dans le noyau Linux de SUSE

d?id=CVE-2022-50304 Référence CVE CVE-2022-50308 https://www.cve.org/CVERecord?id=CVE-2022-50308 Référence CVE CVE-2022-50309 https://www.cve.org/CVERecord?id=CVE-2022-50309 Référence CVE CVE-2022-50311 https://www.cve.org/CVERecord?id=CVE-2022-50311 Référence CVE CVE-2022-50312 https://www.cve.org/CVERecord?id=CVE-2022-50312 Référence CVE CVE-2022-50317 https://www.cve.org/CVERecord?id=CVE-2022-50317 Référence CVE CVE-2022-50318 https://www.cve.org/CVERecord?id=CVE-2022-50318 Référence CVE CVE-2022-50320 https://www.cve.org/CVERecord?id=CVE-2022-50320 Référence CVE CVE-2022-50321 https://www.cve.org/CVERecord?id=CVE-2022-50321 Référence CVE CVE-2022-50323 https://www.cve.org/CVERecord?id=CVE-2022-50323 Référence CVE CVE-2022-50324 https://www.cve.org/CVERecord?id=CVE-2022-50324 Référence CVE CVE-2022-50325 https://www.cve.org/CVERecord?id=CVE-2022-50325 Référence CVE CVE-2022-50328 https://www.cve.org/CVERecord?id=CVE-2022-50328 Référence CVE CVE-2022-50329 https://www.cve.org/CVERecord?id=CVE-2022-50329 Référence CVE CVE-2022-50330 https://www.cve.org/CVERecord?id=CVE-2022-50330 Référence CVE CVE-2022-50331 https://www.cve.org/CVERecord?id=CVE-2022-50331 Référence CVE CVE-2022-50333 https://www.cve.org/CVERecord?id=CVE-2022-50333 Référence CVE CVE-2022-50339 https://www.cve.org/CVERecord?id=

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
8527c9a6bf8e54fef0a8d3d7d8874a48c725c915 < 92b4c5c3fa810212da20088bcc6c0a77fc8607bd; 3261400639463a853ba2b3be8bd009c2a8089775 < 847a2859814b31392340a2b16604b25afaa92dcc; 3261400639463a853ba2b3be8bd009c2a8089775 < 228ebc41dfab5b5d34cd76835ddb0ca8ee12f513; 6730c48ed6b0cd939fc9b30b2d621ce0b89bea83; 5.15.68 < 5.15.77; 5.19.9 < 5.20; 6.0
Fixed
< 6.0; 5.15.77 ≤ 5.15.*; 6.0.7 ≤ 6.0.*; 6.1 ≤ *
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 15 Sept 2025 · Last source change 23 May 2026, 15:24 UTC · CWE not yet assigned

CVE recordCVE.org · 5.2
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2022-55532
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceUnavailable
NVD statusNVD enriched

Missing structured fields: CWE classification. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2022-50323 · cve.blacktree.nl