CVE-2024-26635: Linux kernel · llc: Drop support for ETH_P_TR_802_2.
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 4.4.0-1131.137 : update Linux kernel when convenient.
Data as of 28 Oct 2026, 10:59 UTC
- Patch
- Available – fixed in 4.4.0-1131.137, 4.15.0-1177.192~14.04.1, 4.4.0-254.288~14.04.1 +82
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 18 Mar 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-6766-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6767-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6767-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6774-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6777-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6778-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6777-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6777-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6777-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-6795-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu Pro Realtime 24.04 LTSlinux-raspi-realtimepkg:deb/ubuntu/linux-raspi-realtime?arch=source&distro=realtime/nobleOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=jammyOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinux-allwinner-5.19pkg:deb/ubuntu/linux-allwinner-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=jammyOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinux-aws-5.19pkg:deb/ubuntu/linux-aws-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-aws-6.2pkg:deb/ubuntu/linux-aws-6.2?arch=source&distro=jammyOther 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: llc: Drop support for ETH_P_TR_802_2. syzbot reported an uninit-value bug below. [0] llc supports ETH_P_802_2 (0x0004) and used to support ETH_P_TR_802_2 (0x0011), and syzbot abused the latter to trigger the bug. write$tun(r0, &(0x7f0000000040)={@val={0x0, 0x11}, @val, @mpls={[], @llc={@snap={0xaa, 0x1, ')', "90e5dd"}}}}, 0x16) llc_conn_handler() initialises local variables {saddr,daddr}.mac based on skb in llc_pdu_decode_sa()/llc_pdu_decode_da() and passes them to __llc_lookup(). However, the initialisation is done only when skb->protocol is htons(ETH_P_802_2), otherwise, __llc_lookup_established() and __llc_lookup_listener() will read garbage. The missing initialisation existed prior to commit 211ed865108e ("net: delete all instances of special processing for token ring"). It removed the part to kick out the token ring stuff but forgot to close the door allowing ETH_P_TR_802_2 packets to sneak into llc_rcv(). Let's remove llc_tr_packet_type and complete the deprecation. [0]: BUG: KMSAN: uninit-value in __llc_lookup_established+0xe9d/0xf90 __llc_lookup_established+0xe9d/0xf90 __llc_lookup net/llc/llc_conn.c:611 [inline] llc_conn_handler+0x4bd/0x1360 net/llc/llc_conn.c:791 llc_rcv+0xfbb/0x14a0 net/llc/llc_input.c:206 __netif_receive_skb_one_core net/core/dev.c:5527 [inline] __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5641 netif_receive_skb_internal net/core/dev.c:5727 [inline] netif_receive_skb+0x58/0x660 net/core/dev.c:5786 tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555 tun_get_user+0x53af/0x66d0 drivers/net/tun.c:2002 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2020 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x8ef/0x1490 fs/read_write.c:584 ksys_write+0x20f/0x4c0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x93/0xd0 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b Local variable daddr created at: llc_conn_handler+0x53/0x1360 net/llc/llc_conn.c:783 llc_rcv+0xfbb/0x14a0 net/llc/llc_input.c:206 CPU: 1 PID: 5004 Comm: syz-executor994 Not tainted 6.6.0-syzkaller-14500-g1c41041124bd #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
References
- ubuntu.com/security/CVE-2024-26635 (opens in a new tab)
- git.kernel.org/linus/e3f9bed9bee261e3347131764e42aeedf1ffea61 (opens in a new tab)
- git.kernel.org/stable/c/165ad1e22779685c3ed3dd349c6c4c632309cc62 (opens in a new tab)
- git.kernel.org/stable/c/b8e8838f82f332ae80c643dbb1ca4418d0628097 (opens in a new tab)
- git.kernel.org/stable/c/9ccdef19cf9497c2803b005369668feb91cacdfd (opens in a new tab)
- git.kernel.org/stable/c/c0fe2fe7a5a291dfcf6dc64301732c8d3dc6a828 (opens in a new tab)
- git.kernel.org/stable/c/660c3053d992b68fee893a0e9ec9159228cffdc6 (opens in a new tab)
- git.kernel.org/stable/c/f1f34a515fb1e25e85dee94f781e7869ae351fb8 (opens in a new tab)
- git.kernel.org/stable/c/df57fc2f2abf548aa889a36ab0bdcc94a75399dc (opens in a new tab)
- git.kernel.org/stable/c/e3f9bed9bee261e3347131764e42aeedf1ffea61 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-26635 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6767-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6767-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6774-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6777-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6778-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6777-2 (opens in a new tab)