{
  "threat_severity" : "Moderate",
  "public_date" : "2026-06-24T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: net: qrtr: fix refcount saturation and potential UAF in qrtr_port_remove",
    "id" : "2492432",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2492432"
  },
  "cvss3" : {
    "cvss3_base_score" : "7.0",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-911",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nnet: qrtr: fix refcount saturation and potential UAF in qrtr_port_remove\nIn qrtr_port_remove(), the socket reference count is decremented via\n__sock_put() before the port is removed from the qrtr_ports XArray and\nbefore the RCU grace period elapses.\nThis breaks the fundamental RCU update paradigm. It exposes a race\nwindow where a concurrent RCU reader (such as qrtr_reset_ports() or\nqrtr_port_lookup()) can obtain a pointer to the socket from the XArray,\nand attempt to call sock_hold() on a socket whose reference count has\nalready dropped to zero.\nThis exact race condition was hit during syzkaller fuzzing, leading to\nthe following refcount saturation warning and a potential Use-After-Free:\nrefcount_t: saturated; leaking memory.\nWARNING: CPU: 3 PID: 1273 at lib/refcount.c:22 refcount_warn_saturate+0xae/0x1d0\nModules linked in: qrtr(+) bochs drm_shmem_helper ...\nCall Trace:\n<TASK>\nqrtr_reset_ports net/qrtr/af_qrtr.c:768 [inline] [qrtr]\n__qrtr_bind.isra.0+0x48b/0x570 net/qrtr/af_qrtr.c:805 [qrtr]\nqrtr_bind+0x17d/0x210 net/qrtr/af_qrtr.c:901 [qrtr]\nkernel_bind+0xe4/0x120 net/socket.c:3592\nqrtr_ns_init+0x1a6/0x380 net/qrtr/ns.c:715 [qrtr]\nqrtr_proto_init+0x3b/0xff0 net/qrtr/af_qrtr.c:169 [qrtr]\ndo_one_initcall+0xf5/0x5e0 init/main.c:1283\n...\n</TASK>\nFix this by deferring the reference count decrement until after the\nxa_erase() and the synchronize_rcu() complete.\n(Note: The v1 of this patch incorrectly replaced __sock_put() with\nsock_put(). As Simon Horman pointed out, the callers of qrtr_port_remove()\nstill hold a reference to the socket, so freeing the socket memory here\nwould lead to a subsequent UAF in the caller. Thus, the __sock_put() is\nkept, but only repositioned to close the RCU race.)", "A flaw was found in the Linux kernel's `qrtr` network subsystem. A race condition exists in the `qrtr_port_remove()` function where the socket reference count is decremented prematurely. This allows a concurrent reader to access a socket whose reference count has dropped to zero, potentially leading to a Use-After-Free (UAF) vulnerability. An attacker could exploit this to cause memory corruption, leading to system instability or a denial of service." ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "release_date" : "2026-09-08T00:00:00Z",
    "advisory" : "RHSA-2026:65334",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10.2",
    "package" : "kernel-0:6.12.0-211.53.1.el10_2"
  } ],
  "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" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-52947\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-52947\nhttps://lore.kernel.org/linux-cve-announce/2026062402-CVE-2026-52947-8205@gregkh/T" ],
  "name" : "CVE-2026-52947",
  "csaw" : false
}