{
  "threat_severity" : "Low",
  "public_date" : "2025-12-09T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: ethtool: Fix uninitialized number of lanes",
    "id" : "2420252",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2420252"
  },
  "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" : "verified"
  },
  "cwe" : "CWE-908",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nethtool: Fix uninitialized number of lanes\nIt is not possible to set the number of lanes when setting link modes\nusing the legacy IOCTL ethtool interface. Since 'struct\nethtool_link_ksettings' is not initialized in this path, drivers receive\nan uninitialized number of lanes in 'struct\nethtool_link_ksettings::lanes'.\nWhen this information is later queried from drivers, it results in the\nethtool code making decisions based on uninitialized memory, leading to\nthe following KMSAN splat [1]. In practice, this most likely only\nhappens with the tun driver that simply returns whatever it got in the\nset operation.\nAs far as I can tell, this uninitialized memory is not leaked to user\nspace thanks to the 'ethtool_ops->cap_link_lanes_supported' check in\nlinkmodes_prepare_data().\nFix by initializing the structure in the IOCTL path. Did not find any\nmore call sites that pass an uninitialized structure when calling\n'ethtool_ops::set_link_ksettings()'.\n[1]\nBUG: KMSAN: uninit-value in ethnl_update_linkmodes net/ethtool/linkmodes.c:273 [inline]\nBUG: KMSAN: uninit-value in ethnl_set_linkmodes+0x190b/0x19d0 net/ethtool/linkmodes.c:333\nethnl_update_linkmodes net/ethtool/linkmodes.c:273 [inline]\nethnl_set_linkmodes+0x190b/0x19d0 net/ethtool/linkmodes.c:333\nethnl_default_set_doit+0x88d/0xde0 net/ethtool/netlink.c:640\ngenl_family_rcv_msg_doit net/netlink/genetlink.c:968 [inline]\ngenl_family_rcv_msg net/netlink/genetlink.c:1048 [inline]\ngenl_rcv_msg+0x141a/0x14c0 net/netlink/genetlink.c:1065\nnetlink_rcv_skb+0x3f8/0x750 net/netlink/af_netlink.c:2577\ngenl_rcv+0x40/0x60 net/netlink/genetlink.c:1076\nnetlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]\nnetlink_unicast+0xf41/0x1270 net/netlink/af_netlink.c:1365\nnetlink_sendmsg+0x127d/0x1430 net/netlink/af_netlink.c:1942\nsock_sendmsg_nosec net/socket.c:724 [inline]\nsock_sendmsg net/socket.c:747 [inline]\n____sys_sendmsg+0xa24/0xe40 net/socket.c:2501\n___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2555\n__sys_sendmsg net/socket.c:2584 [inline]\n__do_sys_sendmsg net/socket.c:2593 [inline]\n__se_sys_sendmsg net/socket.c:2591 [inline]\n__x64_sys_sendmsg+0x36b/0x540 net/socket.c:2591\ndo_syscall_x64 arch/x86/entry/common.c:50 [inline]\ndo_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80\nentry_SYSCALL_64_after_hwframe+0x63/0xcd\nUninit was stored to memory at:\ntun_get_link_ksettings+0x37/0x60 drivers/net/tun.c:3544\n__ethtool_get_link_ksettings+0x17b/0x260 net/ethtool/ioctl.c:441\nethnl_set_linkmodes+0xee/0x19d0 net/ethtool/linkmodes.c:327\nethnl_default_set_doit+0x88d/0xde0 net/ethtool/netlink.c:640\ngenl_family_rcv_msg_doit net/netlink/genetlink.c:968 [inline]\ngenl_family_rcv_msg net/netlink/genetlink.c:1048 [inline]\ngenl_rcv_msg+0x141a/0x14c0 net/netlink/genetlink.c:1065\nnetlink_rcv_skb+0x3f8/0x750 net/netlink/af_netlink.c:2577\ngenl_rcv+0x40/0x60 net/netlink/genetlink.c:1076\nnetlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]\nnetlink_unicast+0xf41/0x1270 net/netlink/af_netlink.c:1365\nnetlink_sendmsg+0x127d/0x1430 net/netlink/af_netlink.c:1942\nsock_sendmsg_nosec net/socket.c:724 [inline]\nsock_sendmsg net/socket.c:747 [inline]\n____sys_sendmsg+0xa24/0xe40 net/socket.c:2501\n___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2555\n__sys_sendmsg net/socket.c:2584 [inline]\n__do_sys_sendmsg net/socket.c:2593 [inline]\n__se_sys_sendmsg net/socket.c:2591 [inline]\n__x64_sys_sendmsg+0x36b/0x540 net/socket.c:2591\ndo_syscall_x64 arch/x86/entry/common.c:50 [inline]\ndo_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80\nentry_SYSCALL_64_after_hwframe+0x63/0xcd\nUninit was stored to memory at:\ntun_set_link_ksettings+0x37/0x60 drivers/net/tun.c:3553\nethtool_set_link_ksettings+0x600/0x690 net/ethtool/ioctl.c:609\n__dev_ethtool net/ethtool/ioctl.c:3024 [inline]\ndev_ethtool+0x1db9/0x2a70 net/ethtool/ioctl.c:3078\ndev_ioctl+0xb07/0x1270 net/core/dev_ioctl.c:524\nsock_do_ioctl+0x295/0x540 net/socket.c:1213\nsock_i\n---truncated---" ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2024-05-22T00:00:00Z",
    "advisory" : "RHSA-2024:3138",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-553.el8_10"
  } ],
  "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" : "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-2023-53798\nhttps://nvd.nist.gov/vuln/detail/CVE-2023-53798\nhttps://lore.kernel.org/linux-cve-announce/2025120942-CVE-2023-53798-7845@gregkh/T" ],
  "name" : "CVE-2023-53798",
  "csaw" : false
}