GHSA-VGRC-X22Q-WC53

Vulnerability from github – Published: 2026-06-24 09:30 – Updated: 2026-07-08 21:30
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix NULL pointer dereference in bpf_sk_storage_clone and diag paths

bpf_selem_unlink_nofail() sets SDATA(selem)->smap to NULL before removing the selem from the storage hlist. A concurrent RCU reader in bpf_sk_storage_clone() can observe the selem still on the list with smap already NULL, causing a NULL pointer dereference.

general protection fault, probably for non-canonical address 0xdffffc000000000a: KASAN: null-ptr-deref in range [0x0000000000000050-0x0000000000000057] RIP: 0010:bpf_sk_storage_clone+0x1cd/0xaa0 net/core/bpf_sk_storage.c:174 Call Trace: sk_clone+0xfed/0x1980 net/core/sock.c:2591 inet_csk_clone_lock+0x30/0x760 net/ipv4/inet_connection_sock.c:1222 tcp_create_openreq_child+0x35/0x2680 net/ipv4/tcp_minisocks.c:571 tcp_v4_syn_recv_sock+0x123/0xf90 net/ipv4/tcp_ipv4.c:1729 tcp_check_req+0x8e1/0x2580 include/net/tcp.h:855 tcp_v4_rcv+0x1845/0x3b80 net/ipv4/tcp_ipv4.c:2347

Add a NULL check for smap in bpf_sk_storage_clone().

bpf_sk_storage_diag_put_all() has the same issue. Add a NULL check and pass the validated smap directly to diag_get(), which is refactored to take smap as a parameter instead of reading it internally.

bpf_sk_storage_diag_put() uses diag->maps[i] which is always valid under its refcount, so diag->maps[i] is passed directly to diag_get().

Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-52938"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-476"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-24T08:16:24Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix NULL pointer dereference in bpf_sk_storage_clone and diag paths\n\nbpf_selem_unlink_nofail() sets SDATA(selem)-\u003esmap to NULL before\nremoving the selem from the storage hlist. A concurrent RCU reader in\nbpf_sk_storage_clone() can observe the selem still on the list with\nsmap already NULL, causing a NULL pointer dereference.\n\n general protection fault, probably for non-canonical address 0xdffffc000000000a:\n KASAN: null-ptr-deref in range [0x0000000000000050-0x0000000000000057]\n RIP: 0010:bpf_sk_storage_clone+0x1cd/0xaa0 net/core/bpf_sk_storage.c:174\n Call Trace:\n  \u003cIRQ\u003e\n  sk_clone+0xfed/0x1980 net/core/sock.c:2591\n  inet_csk_clone_lock+0x30/0x760 net/ipv4/inet_connection_sock.c:1222\n  tcp_create_openreq_child+0x35/0x2680 net/ipv4/tcp_minisocks.c:571\n  tcp_v4_syn_recv_sock+0x123/0xf90 net/ipv4/tcp_ipv4.c:1729\n  tcp_check_req+0x8e1/0x2580 include/net/tcp.h:855\n  tcp_v4_rcv+0x1845/0x3b80 net/ipv4/tcp_ipv4.c:2347\n\nAdd a NULL check for smap in bpf_sk_storage_clone().\n\nbpf_sk_storage_diag_put_all() has the same issue. Add a NULL check\nand pass the validated smap directly to diag_get(), which is refactored\nto take smap as a parameter instead of reading it internally.\n\nbpf_sk_storage_diag_put() uses diag-\u003emaps[i] which is always valid\nunder its refcount, so diag-\u003emaps[i] is passed directly to diag_get().",
  "id": "GHSA-vgrc-x22q-wc53",
  "modified": "2026-07-08T21:30:22Z",
  "published": "2026-06-24T09:30:48Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-52938"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/16af24fea29c209dea53595c99f6da9398548e1b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/375e4e33c18dfa05c5dfd5f3dfffeb29343dd4c7"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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