CVE-2024-38538: Linux kernel · net: bridge: xmit: make sure we have at least eth header len bytes
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.3 High · fixed in 4.4.0-1138.144 : patch Linux kernel soon.
Data as of 28 Oct 2026, 10:59 UTC
- Patch
- Available – fixed in 4.4.0-1138.144, 4.15.0-1183.198~14.04.1, 4.4.0-261.295~14.04.1 +91
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:HExploitation evidence
Disclosed: evidence found.
CVE published 19 Jun 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-6949-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6952-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6955-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6949-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6952-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7121-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7121-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7121-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7148-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7159-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7159-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7166-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-ibmpkg:deb/ubuntu/linux-ibm?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
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
References
- ubuntu.com/security/CVE-2024-38538 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-38538 (opens in a new tab)
- git.kernel.org/linus/8bd67ebb50c0145fd2ca8681ab65eb7e8cde1afc (opens in a new tab)
- git.kernel.org/stable/c/28126b83f86ab9cc7936029c2dff845d3dcedba2 (opens in a new tab)
- git.kernel.org/stable/c/1abb371147905ba250b4cc0230c4be7e90bea4d5 (opens in a new tab)
- git.kernel.org/stable/c/f482fd4ce919836a49012b2d31b00fc36e2488f2 (opens in a new tab)
- git.kernel.org/stable/c/5b5d669f569807c7ab07546e73c0741845a2547a (opens in a new tab)
- git.kernel.org/stable/c/8bd67ebb50c0145fd2ca8681ab65eb7e8cde1afc (opens in a new tab)
- ubuntu.com/security/notices/USN-6949-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6952-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6955-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6949-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6952-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7121-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7121-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7121-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7148-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7159-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7159-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7166-1 (opens in a new tab)