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CVE Record

CVE-2022-50259: bpf, sockmap: fix race in sock_map_free()

In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: fix race in sock_map_free() sock_map_free() calls release_sock(sk) without owning a reference on the socket. This can cause use-after-free as syzbot found [1] Jakub Sitnicki already took care of a similar issue in sock_hash_free() in commit 75e68e5bf2c7 ("bpf, sockhash: Synchronize delete from bucket list on map free") [1] refcount_t: decrement hit 0; leaking memory. WARNING: CPU: 0 PID: 3785 at lib/refcount.c:31 refcount_warn_saturate+0x17c/0x1a0 lib/refcount.c:31 Modules linked in: CPU: 0 PID: 3785 Comm: kworker/u4:6 Not tainted 6.1.0-rc7-syzkaller-00103-gef4d3ea40565 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: events_unbound bpf_map_free_deferred RIP: 0010:refcount_warn_saturate+0x17c/0x1a0 lib/refcount.c:31 Code: 68 8b 31 c0 e8 75 71 15 fd 0f 0b e9 64 ff ff ff e8 d9 6e 4e fd c6 05 62 9c 3d 0a 01 48 c7 c7 80 bb 68 8b 31 c0 e8 54 71 15 fd <0f> 0b e9 43 ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c a2 fe ff RSP: 0018:ffffc9000456fb60 EFLAGS: 00010246 RAX: eae59bab72dcd700 RBX: 0000000000000004 RCX: ffff8880207057c0 RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000000 RBP: 0000000000000004 R08: ffffffff816fdabd R09: fffff520008adee5 R10: fffff520008adee5 R11: 1ffff920008adee4 R12: 0000000000000004 R13: dffffc0000000000 R14: ffff88807b1c6c00 R15: 1ffff1100f638dcf FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30c30000 CR3: 000000000d08e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __refcount_dec include/linux/refcount.h:344 [inline] refcount_dec include/linux/refcount.h:359 [inline] __sock_put include/net/sock.h:779 [inline] tcp_release_cb+0x2d0/0x360 net/ipv4/tcp_output.c:1092 release_sock+0xaf/0x1c0 net/core/sock.c:3468 sock_map_free+0x219/0x2c0 net/core/sock_map.c:356 process_one_work+0x81c/0xd10 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 </TASK>

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2022-50259 is a Linux kernel flaw in BPF sockmap cleanup. A race can make the kernel release a socket without holding the needed reference, creating a use-after-free condition. The source bundle does not provide CVSS, confirmed exploit activity, or full distribution impact details.

Executive priority

Schedule remediation through normal kernel patching with elevated attention for shared, container, and cloud workloads. There is no source-backed active exploitation signal, but kernel use-after-free defects carry meaningful reliability and security risk.

Technical view

The issue is in net/core/sock_map.c sock_map_free(). During deferred BPF map free, release_sock(sk) may run without owning a socket reference. The report shows syzbot triggering refcount warnings through tcp_release_cb and release_sock. Stable kernel commits are referenced as fixes.

Likely exposure

Systems running affected Linux kernels with BPF sockmap support may be exposed. The bundle names Linux kernel version markers but does not provide complete range semantics or distribution backport status, so exposure must be checked against vendor kernels and the listed stable commits.

Exploitation context

The bundle says syzbot found the bug and marks KEV as false. It does not cite active exploitation, a public exploit, or a demonstrated attacker impact path. Treat exploitation status as unconfirmed, not actively exploited.

Researcher notes

Evidence is limited to the CVE description, syzbot trace, affected Linux entries, and stable commit references. No CVSS, CWE, exploitability analysis, or distro-specific package mapping is present in the bundle.

Mitigation direction

  • Update to a vendor kernel containing the referenced stable fixes.
  • Check Linux distribution advisories for backported fixes.
  • Prioritize internet-facing and multi-tenant Linux hosts for patch verification.
  • Do not assume upstream version numbers match vendor kernel backports.

Validation and detection

  • Inventory Linux kernel versions across servers and images.
  • Compare installed kernels against vendor advisories and referenced stable commits.
  • Confirm patched kernels are running after reboot, not merely installed.
  • Review BPF usage and sockmap-dependent workloads for affected hosts.
Prepared
Confidence
medium
Sources
8

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.

ATT&CK lookup starting points

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CVE-2022-50259 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
0ADP providers
7Source links

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.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux20ae0cb8983b05136d5293c47fadc99a8ca8ca2d, 7e81a35302066c5a00b4c72d83e3ea4cad6eeb5b, 7e81a35302066c5a00b4c72d83e3ea4cad6eeb5b, 7e81a35302066c5a00b4c72d83e3ea4cad6eeb5b, 7e81a35302066c5a00b4c72d83e3ea4cad6eeb5b, 7e81a35302066c5a00b4c72d83e3ea4cad6eeb5bunaffected
LinuxLinux5.5, 0, 5.4.229, 5.10.163, 5.15.86, 6.0.16, 6.1.2, 6.2affected
Weakness

CWE details

No CWE listed

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