GHSA-PWR6-CVF5-35F3
Vulnerability from github – Published: 2026-06-24 18:32 – Updated: 2026-06-28 09:31In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix same-register dst/src OOB read and pointer leak in sock_ops
When a BPF sock_ops program accesses ctx fields with dst_reg == src_reg, the SOCK_OPS_GET_SK() and SOCK_OPS_GET_FIELD() macros fail to zero the destination register in the !fullsock / !locked_tcp_sock path.
Both macros borrow a temporary register to check is_fullsock / is_locked_tcp_sock when dst_reg == src_reg, because dst_reg holds the ctx pointer. When the check is false (e.g., TCP_NEW_SYN_RECV state with a request_sock), dst_reg should be zeroed but is not, leaving the stale ctx pointer:
-
SOCK_OPS_GET_SK: dst_reg retains the ctx pointer, passes NULL checks as PTR_TO_SOCKET_OR_NULL, and can be used as a bogus socket pointer, leading to stack-out-of-bounds access in helpers like bpf_skc_to_tcp6_sock().
-
SOCK_OPS_GET_FIELD: dst_reg retains the ctx pointer which the verifier believes is a SCALAR_VALUE, leaking a kernel pointer.
Fix both macros by: - Changing JMP_A(1) to JMP_A(2) in the fullsock path to skip the added instruction. - Adding BPF_MOV64_IMM(si->dst_reg, 0) after the temp register restore in the !fullsock path, placed after the restore because dst_reg == src_reg means we need src_reg intact to read ctx->temp.
{
"affected": [],
"aliases": [
"CVE-2026-53078"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-24T17:17:21Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix same-register dst/src OOB read and pointer leak in sock_ops\n\nWhen a BPF sock_ops program accesses ctx fields with dst_reg == src_reg,\nthe SOCK_OPS_GET_SK() and SOCK_OPS_GET_FIELD() macros fail to zero the\ndestination register in the !fullsock / !locked_tcp_sock path.\n\nBoth macros borrow a temporary register to check is_fullsock /\nis_locked_tcp_sock when dst_reg == src_reg, because dst_reg holds the\nctx pointer. When the check is false (e.g., TCP_NEW_SYN_RECV state with\na request_sock), dst_reg should be zeroed but is not, leaving the stale\nctx pointer:\n\n - SOCK_OPS_GET_SK: dst_reg retains the ctx pointer, passes NULL checks\n as PTR_TO_SOCKET_OR_NULL, and can be used as a bogus socket pointer,\n leading to stack-out-of-bounds access in helpers like\n bpf_skc_to_tcp6_sock().\n\n - SOCK_OPS_GET_FIELD: dst_reg retains the ctx pointer which the\n verifier believes is a SCALAR_VALUE, leaking a kernel pointer.\n\nFix both macros by:\n - Changing JMP_A(1) to JMP_A(2) in the fullsock path to skip the\n added instruction.\n - Adding BPF_MOV64_IMM(si-\u003edst_reg, 0) after the temp register\n restore in the !fullsock path, placed after the restore because\n dst_reg == src_reg means we need src_reg intact to read ctx-\u003etemp.",
"id": "GHSA-pwr6-cvf5-35f3",
"modified": "2026-06-28T09:31:41Z",
"published": "2026-06-24T18:32:46Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53078"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/10f86a2a5c91fc4c4d001960f1c21abe52545ef6"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/18e3ffde1822f0b48b1753bf34aa97ce839df1d8"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.