VulnerabilityPublished 18 Mar 2024Updated 28 Oct 2026

CVE-2024-26636: Linux kernel · llc: make llc_ui_sendmsg() more robust against bonding changes

Affects Linux kernelSource GCVE Database

Not known to be exploited · CVSS 5.5 Medium · fixed in 4.4.0-1138.144 : update Linux kernel when convenient.

Data as of 28 Oct 2026, 10:59 UTC

CVSS 3.1 base score

5.5Medium

How severe the flaw is on the 0–10 CVSS scale.

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 +83

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

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Patches and advisories

Affected software

Product	Affected	Fixed in
Ubuntu Pro Realtime 24.04 LTSlinux-raspi-realtime`pkg:deb/ubuntu/linux-raspi-realtime?arch=source&distro=realtime/noble`Other threats	Affected <6.8.0-2001.1	Fixed in 6.8.0-2001.1
Ubuntu 22.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=jammy`Other threats	Affected <5.15.0-106.116	Fixed in 5.15.0-106.116
Ubuntu 22.04 LTSlinux-allwinner-5.19`pkg:deb/ubuntu/linux-allwinner-5.19?arch=source&distro=jammy`Other threats	Affected 5.19.0-1007.7~22.04.1 – 5.19.0-1015.15~22.04.1 8 affected builds	Fixed in–
Ubuntu 22.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=jammy`Other threats	Affected <5.15.0-1061.67	Fixed in 5.15.0-1061.67
Ubuntu 22.04 LTSlinux-aws-5.19`pkg:deb/ubuntu/linux-aws-5.19?arch=source&distro=jammy`Other threats	Affected 5.19.0-1019.20~22.04.1 – 5.19.0-1029.30~22.04.1 10 affected builds	Fixed in–
Ubuntu 22.04 LTSlinux-aws-6.2`pkg:deb/ubuntu/linux-aws-6.2?arch=source&distro=jammy`Other threats	Affected 6.2.0-1005.5~22.04.1 – 6.2.0-1018.18~22.04.1 14 affected builds	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: make llc_ui_sendmsg() more robust against bonding changes syzbot was able to trick llc_ui_sendmsg(), allocating an skb with no headroom, but subsequently trying to push 14 bytes of Ethernet header [1] Like some others, llc_ui_sendmsg() releases the socket lock before calling sock_alloc_send_skb(). Then it acquires it again, but does not redo all the sanity checks that were performed. This fix: - Uses LL_RESERVED_SPACE() to reserve space. - Check all conditions again after socket lock is held again. - Do not account Ethernet header for mtu limitation. [1] skbuff: skb_under_panic: text:ffff800088baa334 len:1514 put:14 head:ffff0000c9c37000 data:ffff0000c9c36ff2 tail:0x5dc end:0x6c0 dev:bond0 kernel BUG at net/core/skbuff.c:193 ! Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 6875 Comm: syz-executor.0 Not tainted 6.7.0-rc8-syzkaller-00101-g0802e17d9aca-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : skb_panic net/core/skbuff.c:189 [inline] pc : skb_under_panic+0x13c/0x140 net/core/skbuff.c:203 lr : skb_panic net/core/skbuff.c:189 [inline] lr : skb_under_panic+0x13c/0x140 net/core/skbuff.c:203 sp : ffff800096f97000 x29: ffff800096f97010 x28: ffff80008cc8d668 x27: dfff800000000000 x26: ffff0000cb970c90 x25: 00000000000005dc x24: ffff0000c9c36ff2 x23: ffff0000c9c37000 x22: 00000000000005ea x21: 00000000000006c0 x20: 000000000000000e x19: ffff800088baa334 x18: 1fffe000368261ce x17: ffff80008e4ed000 x16: ffff80008a8310f8 x15: 0000000000000001 x14: 1ffff00012df2d58 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000001 x10: 0000000000ff0100 x9 : e28a51f1087e8400 x8 : e28a51f1087e8400 x7 : ffff80008028f8d0 x6 : 0000000000000000 x5 : 0000000000000001 x4 : 0000000000000001 x3 : ffff800082b78714 x2 : 0000000000000001 x1 : 0000000100000000 x0 : 0000000000000089 Call trace: skb_panic net/core/skbuff.c:189 [inline] skb_under_panic+0x13c/0x140 net/core/skbuff.c:203 skb_push+0xf0/0x108 net/core/skbuff.c:2451 eth_header+0x44/0x1f8 net/ethernet/eth.c:83 dev_hard_header include/linux/netdevice.h:3188 [inline] llc_mac_hdr_init+0x110/0x17c net/llc/llc_output.c:33 llc_sap_action_send_xid_c+0x170/0x344 net/llc/llc_s_ac.c:85 llc_exec_sap_trans_actions net/llc/llc_sap.c:153 [inline] llc_sap_next_state net/llc/llc_sap.c:182 [inline] llc_sap_state_process+0x1ec/0x774 net/llc/llc_sap.c:209 llc_build_and_send_xid_pkt+0x12c/0x1c0 net/llc/llc_sap.c:270 llc_ui_sendmsg+0x7bc/0xb1c net/llc/af_llc.c:997 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] sock_sendmsg+0x194/0x274 net/socket.c:767 splice_to_socket+0x7cc/0xd58 fs/splice.c:881 do_splice_from fs/splice.c:933 [inline] direct_splice_actor+0xe4/0x1c0 fs/splice.c:1142 splice_direct_to_actor+0x2a0/0x7e4 fs/splice.c:1088 do_splice_direct+0x20c/0x348 fs/splice.c:1194 do_sendfile+0x4bc/0xc70 fs/read_write.c:1254 __do_sys_sendfile64 fs/read_write.c:1322 [inline] __se_sys_sendfile64 fs/read_write.c:1308 [inline] __arm64_sys_sendfile64+0x160/0x3b4 fs/read_write.c:1308 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595 Code: aa1803e6 aa1903e7 a90023f5 94792f6a (d4210000)

GCVE source: db.gcve.eu
OSV ID: UBUNTU-CVE-2024-26636
Osv Schema Version: 1.7.0
Ecosystems: Ubuntu:Pro:14.04:LTS, Ubuntu:Pro:16.04:LTS, Ubuntu:16.04:LTS, Ubuntu:Pro:FIPS-updates:16.04:LTS, Ubuntu:Pro:FIPS:16.04:LTS, Ubuntu:Pro:18.04:LTS, Ubuntu:18.04:LTS, Ubuntu:Pro:FIPS-updates:18.04:LTS, Ubuntu:Pro:FIPS:18.04:LTS, Ubuntu:20.04:LTS, Ubuntu:Pro:FIPS-updates:20.04:LTS, Ubuntu:Pro:FIPS:20.04:LTS, Ubuntu:22.04:LTS, Ubuntu:Nvidia-BlueField:22.04:LTS, Ubuntu:Pro:Realtime:22.04:LTS, Ubuntu:Pro:FIPS-preview:22.04:LTS, Ubuntu:Pro:FIPS-updates:22.04:LTS, Ubuntu:Pro:Realtime:24.04:LTS
CVSS version: 3.1

References

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