CVE-2026-68386 (GCVE-0-2026-68386)

Vulnerability from cvelistv5 – Published: 2026-08-10 12:04 – Updated: 2026-08-19 16:34
VLAI
Title
bpf, sockmap: Reject unhashed UDP sockets on sockmap update
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Reject unhashed UDP sockets on sockmap update UDP sockets get SOCK_RCU_FREE set when (auto-)bound. This means sk_is_refcounted(unbound) = true, while sk_is_refcounted(bound) = false. Because sockmap accepts unbound UDP sockets, a BPF program can increment a socket's refcount via lookup. If the socket is subsequently bound, the transition from unbound to bound causes bpf_sk_release() to skip the decrement of the refcount, causing a memory leak. unreferenced object 0xffff88810bc2eb40 (size 1984): comm "test_progs", pid 2451, jiffies 4295320596 hex dump (first 32 bytes): 7f 00 00 01 7f 00 00 01 d2 04 1b b7 04 d2 00 00 ................ 02 00 01 40 00 00 00 00 00 00 00 00 00 00 00 00 ...@............ backtrace (crc bdee079d): kmem_cache_alloc_noprof+0x557/0x660 sk_prot_alloc+0x69/0x240 sk_alloc+0x30/0x460 inet_create+0x2ce/0xf80 __sock_create+0x25b/0x5c0 __sys_socket+0x119/0x1d0 __x64_sys_socket+0x72/0xd0 do_syscall_64+0xa1/0x5f0 entry_SYSCALL_64_after_hwframe+0x76/0x7e Instead of special-casing for refcounted sockets, reject unhashed UDP sockets during sockmap updates, as there is no benefit to supporting those. This effectively reverts the commit under Fixes, with two exceptions: 1. sock_map_sk_state_allowed() maintains a fall-through `return true`. 2. In the spirit of commit b8b8315e39ff ("bpf, sockmap: Remove unhash handler for BPF sockmap usage"), the proto::unhash BPF handler is not reintroduced. Historical note: this issue is related to commit 67312adc96b5 ("bpf: reject unhashed sockets in bpf_sk_assign").
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 0c48eefae712c2fd91480346a07a1a9cd0f9470b , < 2271276ac5279d2d204be7739a1a28d4ef6cf608 (git)
Affected: 0c48eefae712c2fd91480346a07a1a9cd0f9470b , < 7ffe529e7127411806c8692fb1490f552c629dc2 (git)
Affected: 0c48eefae712c2fd91480346a07a1a9cd0f9470b , < 17b7ef6b86112a4e61cee1e9009a4b318e3225c5 (git)
Affected: 0c48eefae712c2fd91480346a07a1a9cd0f9470b , < 250474c69bc3fc48a5fc21d7c349f279caad947a (git)
Affected: 0c48eefae712c2fd91480346a07a1a9cd0f9470b , < 8692655da369961128658cf8539334b6a960ecb0 (git)
Affected: 0c48eefae712c2fd91480346a07a1a9cd0f9470b , < 66efd3368ae10d05e08fbe6425b50fdec7186ac7 (git)
guessed Create a notification for this product.
Linux Linux Affected: 5.15
Unaffected: 0 , < 5.15 (semver)
Unaffected: 6.1.183 , ≤ 6.1.* (semver)
Unaffected: 6.6.148 , ≤ 6.6.* (semver)
Unaffected: 6.12.101 , ≤ 6.12.* (semver)
Unaffected: 6.18.42 , ≤ 6.18.* (semver)
Unaffected: 7.1.6 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf, sockmap: Reject unhashed UDP sockets on sockmap update\n\nUDP sockets get SOCK_RCU_FREE set when (auto-)bound. This means\nsk_is_refcounted(unbound) = true, while sk_is_refcounted(bound) = false.\n\nBecause sockmap accepts unbound UDP sockets, a BPF program can increment a\nsocket\u0027s refcount via lookup. If the socket is subsequently bound, the\ntransition from unbound to bound causes bpf_sk_release() to skip the\ndecrement of the refcount, causing a memory leak.\n\nunreferenced object 0xffff88810bc2eb40 (size 1984):\n  comm \"test_progs\", pid 2451, jiffies 4295320596\n  hex dump (first 32 bytes):\n    7f 00 00 01 7f 00 00 01 d2 04 1b b7 04 d2 00 00  ................\n    02 00 01 40 00 00 00 00 00 00 00 00 00 00 00 00  ...@............\n  backtrace (crc bdee079d):\n    kmem_cache_alloc_noprof+0x557/0x660\n    sk_prot_alloc+0x69/0x240\n    sk_alloc+0x30/0x460\n    inet_create+0x2ce/0xf80\n    __sock_create+0x25b/0x5c0\n    __sys_socket+0x119/0x1d0\n    __x64_sys_socket+0x72/0xd0\n    do_syscall_64+0xa1/0x5f0\n    entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nInstead of special-casing for refcounted sockets, reject unhashed UDP\nsockets during sockmap updates, as there is no benefit to supporting those.\nThis effectively reverts the commit under Fixes, with two exceptions:\n\n1. sock_map_sk_state_allowed() maintains a fall-through `return true`.\n2. In the spirit of commit b8b8315e39ff (\"bpf, sockmap: Remove unhash\n   handler for BPF sockmap usage\"), the proto::unhash BPF handler is not\n   reintroduced.\n\nHistorical note: this issue is related to commit 67312adc96b5 (\"bpf: reject\nunhashed sockets in bpf_sk_assign\")."
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        "dateUpdated": "2026-08-19T16:34:40.363Z",
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    "cveId": "CVE-2026-68386",
    "datePublished": "2026-08-10T12:04:05.306Z",
    "dateReserved": "2026-07-30T09:28:09.388Z",
    "dateUpdated": "2026-08-19T16:34:40.363Z",
    "state": "PUBLISHED"
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If the socket is subsequently bound, the\\ntransition from unbound to bound causes bpf_sk_release() to skip the\\ndecrement of the refcount, causing a memory leak.\\n\\nunreferenced object 0xffff88810bc2eb40 (size 1984):\\n  comm \\\"test_progs\\\", pid 2451, jiffies 4295320596\\n  hex dump (first 32 bytes):\\n    7f 00 00 01 7f 00 00 01 d2 04 1b b7 04 d2 00 00  ................\\n    02 00 01 40 00 00 00 00 00 00 00 00 00 00 00 00  ...@............\\n  backtrace (crc bdee079d):\\n    kmem_cache_alloc_noprof+0x557/0x660\\n    sk_prot_alloc+0x69/0x240\\n    sk_alloc+0x30/0x460\\n    inet_create+0x2ce/0xf80\\n    __sock_create+0x25b/0x5c0\\n    __sys_socket+0x119/0x1d0\\n    __x64_sys_socket+0x72/0xd0\\n    do_syscall_64+0xa1/0x5f0\\n    entry_SYSCALL_64_after_hwframe+0x76/0x7e\\n\\nInstead of special-casing for refcounted sockets, reject unhashed UDP\\nsockets during sockmap updates, as there is no benefit to supporting those.\\nThis effectively reverts the commit under Fixes, with two exceptions:\\n\\n1. sock_map_sk_state_allowed() maintains a fall-through `return true`.\\n2. In the spirit of commit b8b8315e39ff (\\\"bpf, sockmap: Remove unhash\\n   handler for BPF sockmap usage\\\"), the proto::unhash BPF handler is not\\n   reintroduced.\\n\\nHistorical note: this issue is related to commit 67312adc96b5 (\\\"bpf: reject\\nunhashed sockets in bpf_sk_assign\\\").\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"net/core/sock_map.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"0c48eefae712c2fd91480346a07a1a9cd0f9470b\",\"lessThan\":\"2271276ac5279d2d204be7739a1a28d4ef6cf608\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0c48eefae712c2fd91480346a07a1a9cd0f9470b\",\"lessThan\":\"7ffe529e7127411806c8692fb1490f552c629dc2\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0c48eefae712c2fd91480346a07a1a9cd0f9470b\",\"lessThan\":\"17b7ef6b86112a4e61cee1e9009a4b318e3225c5\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0c48eefae712c2fd91480346a07a1a9cd0f9470b\",\"lessThan\":\"250474c69bc3fc48a5fc21d7c349f279caad947a\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0c48eefae712c2fd91480346a07a1a9cd0f9470b\",\"lessThan\":\"8692655da369961128658cf8539334b6a960ecb0\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0c48eefae712c2fd91480346a07a1a9cd0f9470b\",\"lessThan\":\"66efd3368ae10d05e08fbe6425b50fdec7186ac7\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"net/core/sock_map.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"5.15\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"5.15\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.183\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.148\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.101\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.42\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.6\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/17b7ef6b86112a4e61cee1e9009a4b318e3225c5\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/2271276ac5279d2d204be7739a1a28d4ef6cf608\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/250474c69bc3fc48a5fc21d7c349f279caad947a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/66efd3368ae10d05e08fbe6425b50fdec7186ac7\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/7ffe529e7127411806c8692fb1490f552c629dc2\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/8692655da369961128658cf8539334b6a960ecb0\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Low",
      "current_release_date": "2026-08-11T13:30:05+00:00",
      "cve": "CVE-2026-68386",
      "id": "CVE-2026-68386",
      "initial_release_date": "2026-08-10T00:00:00+00:00",
      "product_status:known_affected": "184",
      "product_status:known_not_affected": "90",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: bpf, sockmap: Reject unhashed UDP sockets on sockmap update",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68386.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-08-13T01:28:02Z",
      "cve": "CVE-2026-68386",
      "id": "CVE-2026-68386",
      "initial_release_date": "2026-08-12T16:22:18Z",
      "product_status:known_affected": "177",
      "product_status:known_not_affected": "119",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-68386",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-68386.json",
      "version": "3"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • 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.


Detection rules are retrieved from Rulezet.