{
  "threat_severity" : "Moderate",
  "public_date" : "2025-09-15T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: xsk: check IFF_UP earlier in Tx path",
    "id" : "2395413",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2395413"
  },
  "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-476",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nxsk: check IFF_UP earlier in Tx path\nXsk Tx can be triggered via either sendmsg() or poll() syscalls. These\ntwo paths share a call to common function xsk_xmit() which has two\nsanity checks within. A pseudo code example to show the two paths:\n__xsk_sendmsg() :                       xsk_poll():\nif (unlikely(!xsk_is_bound(xs)))        if (unlikely(!xsk_is_bound(xs)))\nreturn -ENXIO;                          return mask;\nif (unlikely(need_wait))                (...)\nreturn -EOPNOTSUPP;                 xsk_xmit()\nmark napi id\n(...)\nxsk_xmit()\nxsk_xmit():\nif (unlikely(!(xs->dev->flags & IFF_UP)))\nreturn -ENETDOWN;\nif (unlikely(!xs->tx))\nreturn -ENOBUFS;\nAs it can be observed above, in sendmsg() napi id can be marked on\ninterface that was not brought up and this causes a NULL ptr\ndereference:\n[31757.505631] BUG: kernel NULL pointer dereference, address: 0000000000000018\n[31757.512710] #PF: supervisor read access in kernel mode\n[31757.517936] #PF: error_code(0x0000) - not-present page\n[31757.523149] PGD 0 P4D 0\n[31757.525726] Oops: 0000 [#1] PREEMPT SMP NOPTI\n[31757.530154] CPU: 26 PID: 95641 Comm: xdpsock Not tainted 6.2.0-rc5+ #40\n[31757.536871] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019\n[31757.547457] RIP: 0010:xsk_sendmsg+0xde/0x180\n[31757.551799] Code: 00 75 a2 48 8b 00 a8 04 75 9b 84 d2 74 69 8b 85 14 01 00 00 85 c0 75 1b 48 8b 85 28 03 00 00 48 8b 80 98 00 00 00 48 8b 40 20 <8b> 40 18 89 85 14 01 00 00 8b bd 14 01 00 00 81 ff 00 01 00 00 0f\n[31757.570840] RSP: 0018:ffffc90034f27dc0 EFLAGS: 00010246\n[31757.576143] RAX: 0000000000000000 RBX: ffffc90034f27e18 RCX: 0000000000000000\n[31757.583389] RDX: 0000000000000001 RSI: ffffc90034f27e18 RDI: ffff88984cf3c100\n[31757.590631] RBP: ffff88984714a800 R08: ffff88984714a800 R09: 0000000000000000\n[31757.597877] R10: 0000000000000001 R11: 0000000000000000 R12: 00000000fffffffa\n[31757.605123] R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000000\n[31757.612364] FS:  00007fb4c5931180(0000) GS:ffff88afdfa00000(0000) knlGS:0000000000000000\n[31757.620571] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[31757.626406] CR2: 0000000000000018 CR3: 000000184b41c003 CR4: 00000000007706e0\n[31757.633648] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n[31757.640894] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n[31757.648139] PKRU: 55555554\n[31757.650894] Call Trace:\n[31757.653385]  <TASK>\n[31757.655524]  sock_sendmsg+0x8f/0xa0\n[31757.659077]  ? sockfd_lookup_light+0x12/0x70\n[31757.663416]  __sys_sendto+0xfc/0x170\n[31757.667051]  ? do_sched_setscheduler+0xdb/0x1b0\n[31757.671658]  __x64_sys_sendto+0x20/0x30\n[31757.675557]  do_syscall_64+0x38/0x90\n[31757.679197]  entry_SYSCALL_64_after_hwframe+0x72/0xdc\n[31757.687969] Code: 8e f6 ff 44 8b 4c 24 2c 4c 8b 44 24 20 41 89 c4 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 3a 44 89 e7 48 89 44 24 08 e8 b5 8e f6 ff 48\n[31757.707007] RSP: 002b:00007ffd49c73c70 EFLAGS: 00000293 ORIG_RAX: 000000000000002c\n[31757.714694] RAX: ffffffffffffffda RBX: 000055a996565380 RCX: 00007fb4c5727c16\n[31757.721939] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003\n[31757.729184] RBP: 0000000000000040 R08: 0000000000000000 R09: 0000000000000000\n[31757.736429] R10: 0000000000000040 R11: 0000000000000293 R12: 0000000000000000\n[31757.743673] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000\n[31757.754940]  </TASK>\nTo fix this, let's make xsk_xmit a function that will be responsible for\ngeneric Tx, where RCU is handled accordingly and pull out sanity checks\nand xs->zc handling. Populate sanity checks to __xsk_sendmsg() and\nxsk_poll()." ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions",
    "release_date" : "2026-01-28T00:00:00Z",
    "advisory" : "RHSA-2026:1441",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.2",
    "package" : "kernel-0:5.14.0-284.154.1.el9_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions",
    "release_date" : "2026-01-28T00:00:00Z",
    "advisory" : "RHSA-2026:1443",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.2::nfv",
    "package" : "kernel-rt-0:5.14.0-284.154.1.rt14.439.el9_2"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10"
  }, {
    "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" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Not 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-2023-53240\nhttps://nvd.nist.gov/vuln/detail/CVE-2023-53240\nhttps://lore.kernel.org/linux-cve-announce/2025091516-CVE-2023-53240-c379@gregkh/T" ],
  "name" : "CVE-2023-53240",
  "csaw" : false
}