{
  "threat_severity" : "Low",
  "public_date" : "2024-05-19T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: bpf: support deferring bpf_link dealloc to after RCU grace period",
    "id" : "2281790",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2281790"
  },
  "cvss3" : {
    "cvss3_base_score" : "5.5",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
    "status" : "draft"
  },
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nbpf: support deferring bpf_link dealloc to after RCU grace period\nBPF link for some program types is passed as a \"context\" which can be\nused by those BPF programs to look up additional information. E.g., for\nmulti-kprobes and multi-uprobes, link is used to fetch BPF cookie values.\nBecause of this runtime dependency, when bpf_link refcnt drops to zero\nthere could still be active BPF programs running accessing link data.\nThis patch adds generic support to defer bpf_link dealloc callback to\nafter RCU GP, if requested. This is done by exposing two different\ndeallocation callbacks, one synchronous and one deferred. If deferred\none is provided, bpf_link_free() will schedule dealloc_deferred()\ncallback to happen after RCU GP.\nBPF is using two flavors of RCU: \"classic\" non-sleepable one and RCU\ntasks trace one. The latter is used when sleepable BPF programs are\nused. bpf_link_free() accommodates that by checking underlying BPF\nprogram's sleepable flag, and goes either through normal RCU GP only for\nnon-sleepable, or through RCU tasks trace GP *and* then normal RCU GP\n(taking into account rcu_trace_implies_rcu_gp() optimization), if BPF\nprogram is sleepable.\nWe use this for multi-kprobe and multi-uprobe links, which dereference\nlink during program run. We also preventively switch raw_tp link to use\ndeferred dealloc callback, as upcoming changes in bpf-next tree expose\nraw_tp link data (specifically, cookie value) to BPF program at runtime\nas well." ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2024-35860\nhttps://nvd.nist.gov/vuln/detail/CVE-2024-35860\nhttps://lore.kernel.org/linux-cve-announce/2024051935-CVE-2024-35860-04fd@gregkh/T" ],
  "name" : "CVE-2024-35860",
  "csaw" : false
}