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CVE Record

CVE-2022-48781: crypto: af_alg - get rid of alg_memory_allocated

In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - get rid of alg_memory_allocated alg_memory_allocated does not seem to be really used. alg_proto does have a .memory_allocated field, but no corresponding .sysctl_mem. This means sk_has_account() returns true, but all sk_prot_mem_limits() users will trigger a NULL dereference [1]. THis was not a problem until SO_RESERVE_MEM addition. general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 1 PID: 3591 Comm: syz-executor153 Not tainted 5.17.0-rc3-syzkaller-00316-gb81b1829e7e3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:sk_prot_mem_limits include/net/sock.h:1523 [inline] RIP: 0010:sock_reserve_memory+0x1d7/0x330 net/core/sock.c:1000 Code: 08 00 74 08 48 89 ef e8 27 20 bb f9 4c 03 7c 24 10 48 8b 6d 00 48 83 c5 08 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 ef e8 fb 1f bb f9 48 8b 6d 00 4c 89 ff 48 RSP: 0018:ffffc90001f1fb68 EFLAGS: 00010202 RAX: 0000000000000001 RBX: ffff88814aabc000 RCX: dffffc0000000000 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff90e18120 RBP: 0000000000000008 R08: dffffc0000000000 R09: fffffbfff21c3025 R10: fffffbfff21c3025 R11: 0000000000000000 R12: ffffffff8d109840 R13: 0000000000001002 R14: 0000000000000001 R15: 0000000000000001 FS: 0000555556e08300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc74416f130 CR3: 0000000073d9e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> sock_setsockopt+0x14a9/0x3a30 net/core/sock.c:1446 __sys_setsockopt+0x5af/0x980 net/socket.c:2176 __do_sys_setsockopt net/socket.c:2191 [inline] __se_sys_setsockopt net/socket.c:2188 [inline] __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2188 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc7440fddc9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe98f07968 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fc7440fddc9 RDX: 0000000000000049 RSI: 0000000000000001 RDI: 0000000000000004 RBP: 0000000000000000 R08: 0000000000000004 R09: 00007ffe98f07990 R10: 0000000020000000 R11: 0000000000000246 R12: 00007ffe98f0798c R13: 00007ffe98f079a0 R14: 00007ffe98f079e0 R15: 0000000000000000 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:sk_prot_mem_limits include/net/sock.h:1523 [inline] RIP: 0010:sock_reserve_memory+0x1d7/0x330 net/core/sock.c:1000 Code: 08 00 74 08 48 89 ef e8 27 20 bb f9 4c 03 7c 24 10 48 8b 6d 00 48 83 c5 08 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 ef e8 fb 1f bb f9 48 8b 6d 00 4c 89 ff 48 RSP: 0018:ffffc90001f1fb68 EFLAGS: 00010202 RAX: 0000000000000001 RBX: ffff88814aabc000 RCX: dffffc0000000000 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff90e18120 RBP: 0000000000000008 R08: dffffc0000000000 R09: fffffbfff21c3025 R10: fffffbfff21c3025 R11: 0000000000000000 R12: ffffffff8d109840 R13: 0000000000001002 R14: 0000000000000001 R15: 0000000000000001 FS: 0000555556e08300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc74416f130 CR3: 0000000073d9e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2022-48781 is a Linux kernel flaw in AF_ALG socket memory accounting that can crash the kernel through a null pointer dereference. The provided evidence points to denial of service risk, not data theft or code execution.

Executive priority

Treat this as a kernel stability risk. It warrants normal patch-cycle priority, with faster action on multi-user or workload-hosting systems where local crash impact is business-relevant.

Technical view

AF_ALG had a memory_allocated field without a matching sysctl_mem configuration. After SO_RESERVE_MEM was added, sk_has_account() could return true and sk_prot_mem_limits() users could dereference NULL, causing a general protection fault in sock_reserve_memory.

Likely exposure

The source marks Linux 5.16 and 5.17-related versions as affected. Practical exposure is most relevant where local processes can use AF_ALG sockets and affected socket options. Distribution kernel backports must be checked separately.

Exploitation context

The bundle does not report CISA KEV status or active exploitation. The crash evidence comes from syzkaller/KASAN output. No source in the bundle establishes remote exploitation, privilege escalation, or weaponized public exploit activity.

Researcher notes

The source evidence is narrow but specific: AF_ALG memory accounting can reach sk_prot_mem_limits without valid memory limits. The most defensible impact from the bundle is local kernel denial of service. More impact claims need vendor or maintainer confirmation.

Mitigation direction

  • Update Linux kernels to vendor builds containing the referenced stable fixes.
  • Check distribution advisories for backported fixes that keep older version strings.
  • Prioritize shared hosts, container platforms, and systems running untrusted local code.
  • If patching is delayed, review vendor guidance for AF_ALG or socket-option hardening.

Validation and detection

  • Inventory Linux kernel versions and map them against vendor fixed builds.
  • Confirm whether deployed kernels include the referenced upstream stable commits.
  • Review crash logs for general protection faults in sock_reserve_memory or sk_prot_mem_limits.
  • Verify patch status through OS package metadata, not only uname output.
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

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

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CVE-2022-48781 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
LinuxLinux2bb2f5fb21b0486ff69b7b4a1fe03a760527d133, 2bb2f5fb21b0486ff69b7b4a1fe03a760527d133unaffected
LinuxLinux5.16, 0, 5.16.11, 5.17affected
Weakness

CWE details

No CWE listed

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