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GHSA-46Q5-WP2G-GV63

Vulnerability from github – Published: 2024-06-19 15:30 – Updated: 2025-11-03 21:31
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

net: bridge: xmit: make sure we have at least eth header len bytes

syzbot triggered an uninit value[1] error in bridge device's xmit path by sending a short (less than ETH_HLEN bytes) skb. To fix it check if we can actually pull that amount instead of assuming.

Tested with dropwatch: drop at: br_dev_xmit+0xb93/0x12d0 [bridge] (0xffffffffc06739b3) origin: software timestamp: Mon May 13 11:31:53 2024 778214037 nsec protocol: 0x88a8 length: 2 original length: 2 drop reason: PKT_TOO_SMALL

[1] BUG: KMSAN: uninit-value in br_dev_xmit+0x61d/0x1cb0 net/bridge/br_device.c:65 br_dev_xmit+0x61d/0x1cb0 net/bridge/br_device.c:65 __netdev_start_xmit include/linux/netdevice.h:4903 [inline] netdev_start_xmit include/linux/netdevice.h:4917 [inline] xmit_one net/core/dev.c:3531 [inline] dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3547 __dev_queue_xmit+0x34db/0x5350 net/core/dev.c:4341 dev_queue_xmit include/linux/netdevice.h:3091 [inline] __bpf_tx_skb net/core/filter.c:2136 [inline] __bpf_redirect_common net/core/filter.c:2180 [inline] __bpf_redirect+0x14a6/0x1620 net/core/filter.c:2187 _bpfclone_redirect net/core/filter.c:2460 [inline] bpf_clone_redirect+0x328/0x470 net/core/filter.c:2432 _bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997 __bpf_prog_run512+0xb5/0xe0 kernel/bpf/core.c:2238 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] bpf_test_run+0x499/0xc30 net/bpf/test_run.c:425 bpf_prog_test_run_skb+0x14ea/0x1f20 net/bpf/test_run.c:1058 bpf_prog_test_run+0x6b7/0xad0 kernel/bpf/syscall.c:4269 __sys_bpf+0x6aa/0xd90 kernel/bpf/syscall.c:5678 __do_sys_bpf kernel/bpf/syscall.c:5767 [inline] __se_sys_bpf kernel/bpf/syscall.c:5765 [inline] __x64_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5765 x64_sys_call+0x96b/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Severity
7.1 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Show details on source website
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{
  "affected": [],
  "aliases": [
    "CVE-2024-38538"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-908"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-06-19T14:15:14Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bridge: xmit: make sure we have at least eth header len bytes\n\nsyzbot triggered an uninit value[1] error in bridge device\u0027s xmit path\nby sending a short (less than ETH_HLEN bytes) skb. To fix it check if\nwe can actually pull that amount instead of assuming.\n\nTested with dropwatch:\n drop at: br_dev_xmit+0xb93/0x12d0 [bridge] (0xffffffffc06739b3)\n origin: software\n timestamp: Mon May 13 11:31:53 2024 778214037 nsec\n protocol: 0x88a8\n length: 2\n original length: 2\n drop reason: PKT_TOO_SMALL\n\n[1]\nBUG: KMSAN: uninit-value in br_dev_xmit+0x61d/0x1cb0 net/bridge/br_device.c:65\n br_dev_xmit+0x61d/0x1cb0 net/bridge/br_device.c:65\n __netdev_start_xmit include/linux/netdevice.h:4903 [inline]\n netdev_start_xmit include/linux/netdevice.h:4917 [inline]\n xmit_one net/core/dev.c:3531 [inline]\n dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3547\n __dev_queue_xmit+0x34db/0x5350 net/core/dev.c:4341\n dev_queue_xmit include/linux/netdevice.h:3091 [inline]\n __bpf_tx_skb net/core/filter.c:2136 [inline]\n __bpf_redirect_common net/core/filter.c:2180 [inline]\n __bpf_redirect+0x14a6/0x1620 net/core/filter.c:2187\n ____bpf_clone_redirect net/core/filter.c:2460 [inline]\n bpf_clone_redirect+0x328/0x470 net/core/filter.c:2432\n ___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997\n __bpf_prog_run512+0xb5/0xe0 kernel/bpf/core.c:2238\n bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]\n __bpf_prog_run include/linux/filter.h:657 [inline]\n bpf_prog_run include/linux/filter.h:664 [inline]\n bpf_test_run+0x499/0xc30 net/bpf/test_run.c:425\n bpf_prog_test_run_skb+0x14ea/0x1f20 net/bpf/test_run.c:1058\n bpf_prog_test_run+0x6b7/0xad0 kernel/bpf/syscall.c:4269\n __sys_bpf+0x6aa/0xd90 kernel/bpf/syscall.c:5678\n __do_sys_bpf kernel/bpf/syscall.c:5767 [inline]\n __se_sys_bpf kernel/bpf/syscall.c:5765 [inline]\n __x64_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5765\n x64_sys_call+0x96b/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:322\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f",
  "id": "GHSA-46q5-wp2g-gv63",
  "modified": "2025-11-03T21:31:08Z",
  "published": "2024-06-19T15:30:52Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-38538"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1abb371147905ba250b4cc0230c4be7e90bea4d5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/28126b83f86ab9cc7936029c2dff845d3dcedba2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3e01fc3c66e65d9afe98f1489047a1b2dd8741ca"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5b5d669f569807c7ab07546e73c0741845a2547a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/82090f94c723dab724b1c32db406091d40448a17"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8bd67ebb50c0145fd2ca8681ab65eb7e8cde1afc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b2b7c43cd32080221bb233741bd6011983fe7c11"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c964429ef53f42098a6545a5dabeb1441c1e821d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f482fd4ce919836a49012b2d31b00fc36e2488f2"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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