CVE-2024-38538

2024-06-1914:15:14

CWE-908

Linux

web.nvd.nist.gov

linux kernel

net bridge xmit

vulnerability

resolved

network protocol

CVSS3

7.1

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

AI Score

6.5

Confidence

Low

EPSS

Percentile

5.1%

JSON

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
____bpf_clone_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

Affected configurations

Nvd

Vulners

Node

linuxlinux_kernelRange2.6.12–6.1.93

linuxlinux_kernelRange6.2–6.6.33

linuxlinux_kernelRange6.7–6.8.12

linuxlinux_kernelRange6.9–6.9.3

VendorProductVersionCPE
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Vendor	Product	Version	CPE
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/bridge/br_device.c"
    ],
    "versions": [
      {
        "version": "1da177e4c3f4",
        "lessThan": "28126b83f86a",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "1abb37114790",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "f482fd4ce919",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "5b5d669f5698",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "8bd67ebb50c0",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/bridge/br_device.c"
    ],
    "versions": [
      {
        "version": "2.6.12",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "2.6.12",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.1.93",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.33",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.8.12",
        "lessThanOrEqual": "6.8.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.9.3",
        "lessThanOrEqual": "6.9.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.10",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]