FKIE_CVE-2023-53798

Vulnerability from fkie_nvd - Published: 2025-12-09 01:16 - Updated: 2025-12-09 18:37
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: ethtool: Fix uninitialized number of lanes It is not possible to set the number of lanes when setting link modes using the legacy IOCTL ethtool interface. Since 'struct ethtool_link_ksettings' is not initialized in this path, drivers receive an uninitialized number of lanes in 'struct ethtool_link_ksettings::lanes'. When this information is later queried from drivers, it results in the ethtool code making decisions based on uninitialized memory, leading to the following KMSAN splat [1]. In practice, this most likely only happens with the tun driver that simply returns whatever it got in the set operation. As far as I can tell, this uninitialized memory is not leaked to user space thanks to the 'ethtool_ops->cap_link_lanes_supported' check in linkmodes_prepare_data(). Fix by initializing the structure in the IOCTL path. Did not find any more call sites that pass an uninitialized structure when calling 'ethtool_ops::set_link_ksettings()'. [1] BUG: KMSAN: uninit-value in ethnl_update_linkmodes net/ethtool/linkmodes.c:273 [inline] BUG: KMSAN: uninit-value in ethnl_set_linkmodes+0x190b/0x19d0 net/ethtool/linkmodes.c:333 ethnl_update_linkmodes net/ethtool/linkmodes.c:273 [inline] ethnl_set_linkmodes+0x190b/0x19d0 net/ethtool/linkmodes.c:333 ethnl_default_set_doit+0x88d/0xde0 net/ethtool/netlink.c:640 genl_family_rcv_msg_doit net/netlink/genetlink.c:968 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1048 [inline] genl_rcv_msg+0x141a/0x14c0 net/netlink/genetlink.c:1065 netlink_rcv_skb+0x3f8/0x750 net/netlink/af_netlink.c:2577 genl_rcv+0x40/0x60 net/netlink/genetlink.c:1076 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0xf41/0x1270 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x127d/0x1430 net/netlink/af_netlink.c:1942 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] ____sys_sendmsg+0xa24/0xe40 net/socket.c:2501 ___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2555 __sys_sendmsg net/socket.c:2584 [inline] __do_sys_sendmsg net/socket.c:2593 [inline] __se_sys_sendmsg net/socket.c:2591 [inline] __x64_sys_sendmsg+0x36b/0x540 net/socket.c:2591 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Uninit was stored to memory at: tun_get_link_ksettings+0x37/0x60 drivers/net/tun.c:3544 __ethtool_get_link_ksettings+0x17b/0x260 net/ethtool/ioctl.c:441 ethnl_set_linkmodes+0xee/0x19d0 net/ethtool/linkmodes.c:327 ethnl_default_set_doit+0x88d/0xde0 net/ethtool/netlink.c:640 genl_family_rcv_msg_doit net/netlink/genetlink.c:968 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1048 [inline] genl_rcv_msg+0x141a/0x14c0 net/netlink/genetlink.c:1065 netlink_rcv_skb+0x3f8/0x750 net/netlink/af_netlink.c:2577 genl_rcv+0x40/0x60 net/netlink/genetlink.c:1076 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0xf41/0x1270 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x127d/0x1430 net/netlink/af_netlink.c:1942 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] ____sys_sendmsg+0xa24/0xe40 net/socket.c:2501 ___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2555 __sys_sendmsg net/socket.c:2584 [inline] __do_sys_sendmsg net/socket.c:2593 [inline] __se_sys_sendmsg net/socket.c:2591 [inline] __x64_sys_sendmsg+0x36b/0x540 net/socket.c:2591 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Uninit was stored to memory at: tun_set_link_ksettings+0x37/0x60 drivers/net/tun.c:3553 ethtool_set_link_ksettings+0x600/0x690 net/ethtool/ioctl.c:609 __dev_ethtool net/ethtool/ioctl.c:3024 [inline] dev_ethtool+0x1db9/0x2a70 net/ethtool/ioctl.c:3078 dev_ioctl+0xb07/0x1270 net/core/dev_ioctl.c:524 sock_do_ioctl+0x295/0x540 net/socket.c:1213 sock_i ---truncated---
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6456d80045d6de47734b1a3879c91f72af186529
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/72808c4ab5fd01bf1214195005e15b434bf55cef
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/942a2a0184f7bb1c1ae4bbc556559c86c054b0d2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9ad685dbfe7e856bbf17a7177b64676d324d6ed7
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/da81af0ef8092ecacd87fac3229c29e2e0ce39fd
Impacted products
Vendor Product Version
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nethtool: Fix uninitialized number of lanes\n\nIt is not possible to set the number of lanes when setting link modes\nusing the legacy IOCTL ethtool interface. Since \u0027struct\nethtool_link_ksettings\u0027 is not initialized in this path, drivers receive\nan uninitialized number of lanes in \u0027struct\nethtool_link_ksettings::lanes\u0027.\n\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.\n\nAs far as I can tell, this uninitialized memory is not leaked to user\nspace thanks to the \u0027ethtool_ops-\u003ecap_link_lanes_supported\u0027 check in\nlinkmodes_prepare_data().\n\nFix by initializing the structure in the IOCTL path. Did not find any\nmore call sites that pass an uninitialized structure when calling\n\u0027ethtool_ops::set_link_ksettings()\u0027.\n\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\n ethnl_update_linkmodes net/ethtool/linkmodes.c:273 [inline]\n ethnl_set_linkmodes+0x190b/0x19d0 net/ethtool/linkmodes.c:333\n ethnl_default_set_doit+0x88d/0xde0 net/ethtool/netlink.c:640\n genl_family_rcv_msg_doit net/netlink/genetlink.c:968 [inline]\n genl_family_rcv_msg net/netlink/genetlink.c:1048 [inline]\n genl_rcv_msg+0x141a/0x14c0 net/netlink/genetlink.c:1065\n netlink_rcv_skb+0x3f8/0x750 net/netlink/af_netlink.c:2577\n genl_rcv+0x40/0x60 net/netlink/genetlink.c:1076\n netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]\n netlink_unicast+0xf41/0x1270 net/netlink/af_netlink.c:1365\n netlink_sendmsg+0x127d/0x1430 net/netlink/af_netlink.c:1942\n sock_sendmsg_nosec net/socket.c:724 [inline]\n sock_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\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nUninit was stored to memory at:\n tun_get_link_ksettings+0x37/0x60 drivers/net/tun.c:3544\n __ethtool_get_link_ksettings+0x17b/0x260 net/ethtool/ioctl.c:441\n ethnl_set_linkmodes+0xee/0x19d0 net/ethtool/linkmodes.c:327\n ethnl_default_set_doit+0x88d/0xde0 net/ethtool/netlink.c:640\n genl_family_rcv_msg_doit net/netlink/genetlink.c:968 [inline]\n genl_family_rcv_msg net/netlink/genetlink.c:1048 [inline]\n genl_rcv_msg+0x141a/0x14c0 net/netlink/genetlink.c:1065\n netlink_rcv_skb+0x3f8/0x750 net/netlink/af_netlink.c:2577\n genl_rcv+0x40/0x60 net/netlink/genetlink.c:1076\n netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]\n netlink_unicast+0xf41/0x1270 net/netlink/af_netlink.c:1365\n netlink_sendmsg+0x127d/0x1430 net/netlink/af_netlink.c:1942\n sock_sendmsg_nosec net/socket.c:724 [inline]\n sock_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\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nUninit was stored to memory at:\n tun_set_link_ksettings+0x37/0x60 drivers/net/tun.c:3553\n ethtool_set_link_ksettings+0x600/0x690 net/ethtool/ioctl.c:609\n __dev_ethtool net/ethtool/ioctl.c:3024 [inline]\n dev_ethtool+0x1db9/0x2a70 net/ethtool/ioctl.c:3078\n dev_ioctl+0xb07/0x1270 net/core/dev_ioctl.c:524\n sock_do_ioctl+0x295/0x540 net/socket.c:1213\n sock_i\n---truncated---"
    }
  ],
  "id": "CVE-2023-53798",
  "lastModified": "2025-12-09T18:37:13.640",
  "metrics": {},
  "published": "2025-12-09T01:16:51.470",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6456d80045d6de47734b1a3879c91f72af186529"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/72808c4ab5fd01bf1214195005e15b434bf55cef"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/942a2a0184f7bb1c1ae4bbc556559c86c054b0d2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9ad685dbfe7e856bbf17a7177b64676d324d6ed7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/da81af0ef8092ecacd87fac3229c29e2e0ce39fd"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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