UBUNTU-CVE-2025-38181: High severity ubuntu/linux-azure vulnerability

Q: Which systems are most relevant to this issue?

The issue affects the listed Ubuntu Linux kernel packages, including linux, linux-aws-fips, linux-azure-fips, linux-fips, linux-gcp-fips, linux-azure, linux-gcp, and linux-oracle. The vulnerable path involves CALIPSO option handling together with TCP SYN Cookie processing.

Q: What does an attacker need to exploit it?

The severity vector indicates network reachability, low attack complexity, no required privileges, and no user interaction. The failure occurs when CALIPSO request attribute handling encounters a request socket whose listener is NULL in the SYN Cookie case.

Q: What is the security impact?

The reported flaw is a NULL-pointer dereference during CALIPSO option allocation. The provided vector rates availability impact as high and does not indicate confidentiality or integrity impact.

Q: How is the issue addressed?

The fix makes calipso_req_setattr() and calipso_req_delattr() return an error when the SYN Cookie case has no listener socket, rather than dereferencing the NULL socket pointer.

Published Jul 4, 2025

Updated

In the Linux kernel, the following vulnerability has been resolved: calipso: Fix null-ptr-deref in calipsoreq{set,del}attr(). syzkaller reported a null-ptr-deref in sockomalloc() while allocating a CALIPSO option. [0] The NULL is of struct sock, which was fetched by sktofullsk() in calipsoreqsetattr(). Since commit a1a5344ddbe8 ("tcp: avoid two atomic ops for syncookies"), reqsk->rsklistener could be NULL when SYN Cookie is returned to its client, as hinted by the leading SYN Cookie log. Here are 3 options to fix the bug: 1) Return 0 in calipsoreqsetattr() 2) Return an error in calipsoreqsetattr() 3) Alaways set rsklistener 1) is no go as it bypasses LSM, but 2) effectively disables SYN Cookie for CALIPSO. 3) is also no go as there have been many efforts to reduce atomic ops and make TCP robust against DDoS. See also commit 3b24d854cb35 ("tcp/dccp: do not touch listener skrefcnt under synflood"). As of the blamed commit, SYN Cookie already did not need refcounting, and no one has stumbled on the bug for 9 years, so no CALIPSO user will care about SYN Cookie. Let's return an error in calipsoreqsetattr() and calipsoreqdelattr() in the SYN Cookie case. This can be reproduced by [1] on Fedora and now connect() of nc times out. [0]: TCP: requestsockTCPv6: Possible SYN flooding on port [::]:20002. Sending cookies. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] CPU: 3 UID: 0 PID: 12262 Comm: syz.1.2611 Not tainted 6.14.0 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:readpnet include/net/netnamespace.h:406 [inline] RIP: 0010:socknet include/net/sock.h:655 [inline] RIP: 0010:sockkmalloc+0x35/0x170 net/core/sock.c:2806 Code: 89 d5 41 54 55 89 f5 53 48 89 fb e8 25 e3 c6 fd e8 f0 91 e3 00 48 8d 7b 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 26 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b RSP: 0018:ffff88811af89038 EFLAGS: 00010216 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff888105266400 RDX: 0000000000000006 RSI: ffff88800c890000 RDI: 0000000000000030 RBP: 0000000000000050 R08: 0000000000000000 R09: ffff88810526640e R10: ffffed1020a4cc81 R11: ffff88810526640f R12: 0000000000000000 R13: 0000000000000820 R14: ffff888105266400 R15: 0000000000000050 FS: 00007f0653a07640(0000) GS:ffff88811af80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f863ba096f4 CR3: 00000000163c0005 CR4: 0000000000770ef0 PKRU: 80000000 Call Trace: <IRQ> ipv6renewoptions+0x279/0x950 net/ipv6/exthdrs.c:1288 calipsoreqsetattr+0x181/0x340 net/ipv6/calipso.c:1204 calipsoreqsetattr+0x56/0x80 net/netlabel/netlabelcalipso.c:597 netlblreqsetattr+0x18a/0x440 net/netlabel/netlabelkapi.c:1249 selinuxnetlblinetconnrequest+0x1fb/0x320 security/selinux/netlabel.c:342 selinuxinetconnrequest+0x1eb/0x2c0 security/selinux/hooks.c:5551 securityinetconnrequest+0x50/0xa0 security/security.c:4945 tcpv6routereq+0x22c/0x550 net/ipv6/tcpipv6.c:825 tcpconnrequest+0xec8/0x2b70 net/ipv4/tcpinput.c:7275 tcpv6connrequest+0x1e3/0x440 net/ipv6/tcpipv6.c:1328 tcprcvstateprocess+0xafa/0x52b0 net/ipv4/tcpinput.c:6781 tcpv6dorcv+0x8a6/0x1a40 net/ipv6/tcpipv6.c:1667 tcpv6rcv+0x505e/0x5b50 net/ipv6/tcpipv6.c:1904 ip6protocoldeliverrcu+0x17c/0x1da0 net/ipv6/ip6input.c:436 ip6inputfinish+0x103/0x180 net/ipv6/ip6input.c:480 NFHOOK include/linux/netfilter.h:314 [inline] NFHOOK include/linux/netfilter.h:308 [inline] ip6input+0x13c/0x6b0 net/ipv6/ip6input.c:491 dstinput include/net/dst.h:469 [inline] ip6rcvfinish net/ipv6/ip6input.c:79 [inline] ip6rcvfinish+0xb6/0x490 net/ipv6/ip6input.c:69 NFHOOK include/linux/netfilter.h:314 [inline] NFHOOK include/linux/netf ---truncated---

Affected Software

215 affected componentsFixes available

ubuntu/linux-azure*

ubuntu/linux-aws-hwe*

ubuntu/linux-azure*

ubuntu/linux-gcp*

ubuntu/linux-hwe*

ubuntu/linux-hwe-edge*

ubuntu/linux-oracle*

ubuntu/linux*

ubuntu/linux-aws*

ubuntu/linux-aws-5.0*

ubuntu/linux-aws-5.3*

ubuntu/linux-aws-5.4*

ubuntu/linux-azure*

ubuntu/linux-azure-4.15*

ubuntu/linux-azure-5.3*

ubuntu/linux-azure-5.4*

ubuntu/linux-azure-edge*

ubuntu/linux-gcp*

ubuntu/linux-gcp-4.15*

ubuntu/linux-gcp-5.3*

ubuntu/linux-gcp-5.4*

ubuntu/linux-gke-4.15*

ubuntu/linux-gke-5.4*

ubuntu/linux-gkeop-5.4*

ubuntu/linux-hwe*

ubuntu/linux-hwe-5.4*

ubuntu/linux-hwe-edge*

ubuntu/linux-ibm-5.4*

ubuntu/linux-kvm*

ubuntu/linux-oem*

ubuntu/linux-oracle*

ubuntu/linux-oracle-5.0*

ubuntu/linux-oracle-5.3*

ubuntu/linux-oracle-5.4*

ubuntu/linux-raspi-5.4*

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux*

ubuntu/linux-aws*

ubuntu/linux-aws-5.11*

ubuntu/linux-aws-5.13*

ubuntu/linux-aws-5.15<5.15.0-1092.99~20.04.1

5.15.0-1092.99~20.04.1

ubuntu/linux-aws-5.8*

ubuntu/linux-azure*

ubuntu/linux-azure-5.11*

ubuntu/linux-azure-5.13*

ubuntu/linux-azure-5.15<5.15.0-1096.105~20.04.1

5.15.0-1096.105~20.04.1

ubuntu/linux-azure-5.8*

ubuntu/linux-azure-fde*

ubuntu/linux-bluefield*

ubuntu/linux-gcp*

ubuntu/linux-gcp-5.11*

ubuntu/linux-gcp-5.13*

ubuntu/linux-gcp-5.15<5.15.0-1092.101~20.04.1

5.15.0-1092.101~20.04.1

ubuntu/linux-gcp-5.8*

ubuntu/linux-gke*

ubuntu/linux-gke-5.15*

ubuntu/linux-gkeop*

ubuntu/linux-gkeop-5.15*

ubuntu/linux-hwe-5.11*

ubuntu/linux-hwe-5.13*

ubuntu/linux-hwe-5.15<5.15.0-156.166~20.04.1

5.15.0-156.166~20.04.1

ubuntu/linux-hwe-5.8*

ubuntu/linux-ibm*

ubuntu/linux-ibm-5.15<5.15.0-1086.89~20.04.1

5.15.0-1086.89~20.04.1

ubuntu/linux-intel-5.13*

ubuntu/linux-intel-iotg-5.15<5.15.0-1087.93~20.04.1

5.15.0-1087.93~20.04.1

ubuntu/linux-iot*

ubuntu/linux-kvm*

ubuntu/linux-lowlatency-hwe-5.15<5.15.0-156.166~20.04.1

5.15.0-156.166~20.04.1

ubuntu/linux-nvidia-tegra-5.15<5.15.0-1045.45~20.04.1

5.15.0-1045.45~20.04.1

ubuntu/linux-oem-5.10*

ubuntu/linux-oem-5.13*

ubuntu/linux-oem-5.6*

ubuntu/linux-oracle*

ubuntu/linux-oracle-5.11*

ubuntu/linux-oracle-5.13*

ubuntu/linux-oracle-5.15<5.15.0-1090.96~20.04.1

5.15.0-1090.96~20.04.1

ubuntu/linux-oracle-5.8*

ubuntu/linux-raspi*

ubuntu/linux-raspi2*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.11*

ubuntu/linux-riscv-5.15<5.15.0-1087.91~20.04.1

5.15.0-1087.91~20.04.1

ubuntu/linux-riscv-5.8*

ubuntu/linux-xilinx-zynqmp*

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux<5.15.0-156.166

5.15.0-156.166

ubuntu/linux-allwinner-5.19*

ubuntu/linux-aws<5.15.0-1092.99

5.15.0-1092.99

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-aws-6.5*

ubuntu/linux-aws-6.8<6.8.0-1046.49~22.04.1

6.8.0-1046.49~22.04.1

ubuntu/linux-azure<5.15.0-1096.105

5.15.0-1096.105

ubuntu/linux-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-6.5*

ubuntu/linux-azure-6.8<6.8.0-1051.57~22.04.1

6.8.0-1051.57~22.04.1

ubuntu/linux-azure-fde<5.15.0-1096.105.1

5.15.0-1096.105.1

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-azure-fde-6.8<6.8.0-1046.53~22.04.1

6.8.0-1046.53~22.04.1

ubuntu/linux-gcp<5.15.0-1092.101

5.15.0-1092.101

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-gcp-6.5*

ubuntu/linux-gcp-6.8<6.8.0-1047.50~22.04.2

6.8.0-1047.50~22.04.2

ubuntu/linux-gke<5.15.0-1089.95

5.15.0-1089.95

ubuntu/linux-gkeop<5.15.0-1075.83

5.15.0-1075.83

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-hwe-6.5*

ubuntu/linux-hwe-6.8<6.8.0-100.100~22.04.1

6.8.0-100.100~22.04.1

ubuntu/linux-ibm<5.15.0-1086.89

5.15.0-1086.89

ubuntu/linux-ibm-6.8<6.8.0-1044.44~22.04.1

6.8.0-1044.44~22.04.1

ubuntu/linux-intel-iot-realtime*

ubuntu/linux-intel-iotg<5.15.0-1087.93

5.15.0-1087.93

ubuntu/linux-kvm<5.15.0-1088.93

5.15.0-1088.93

ubuntu/linux-lowlatency<5.15.0-156.166

5.15.0-156.166

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-lowlatency-hwe-6.5*

ubuntu/linux-lowlatency-hwe-6.8<6.8.0-100.100.1~22.04.1

6.8.0-100.100.1~22.04.1

ubuntu/linux-nvidia<5.15.0-1087.88

5.15.0-1087.88

ubuntu/linux-nvidia-6.2*

ubuntu/linux-nvidia-6.5*

ubuntu/linux-nvidia-6.8<6.8.0-1046.49~22.04.1

6.8.0-1046.49~22.04.1

ubuntu/linux-nvidia-tegra<5.15.0-1045.45

5.15.0-1045.45

ubuntu/linux-nvidia-tegra-igx<5.15.0-1034.34

5.15.0-1034.34

ubuntu/linux-oem-5.17*

ubuntu/linux-oem-6.0*

ubuntu/linux-oem-6.1*

ubuntu/linux-oem-6.5*

ubuntu/linux-oracle<5.15.0-1090.96

5.15.0-1090.96

ubuntu/linux-oracle-6.5*

ubuntu/linux-oracle-6.8<6.8.0-1043.44~22.04.1

6.8.0-1043.44~22.04.1

ubuntu/linux-raspi<5.15.0-1086.89

5.15.0-1086.89

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-riscv-6.5*

ubuntu/linux-riscv-6.8<6.8.0-100.100~22.04.1

6.8.0-100.100~22.04.1

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-starfive-6.5*

ubuntu/linux-xilinx-zynqmp<5.15.0-1056.60

5.15.0-1056.60

ubuntu/linux-bluefield<5.15.0-1076.78

5.15.0-1076.78

ubuntu/linux-intel-iot-realtime<5.15.0-1085.87

5.15.0-1085.87

ubuntu/linux-realtime<5.15.0-1092.101

5.15.0-1092.101

ubuntu/linux-realtime-6.8<6.8.1-1041.42~22.04.1

6.8.1-1041.42~22.04.1

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips<5.15.0-1092.99+fips1

5.15.0-1092.99+fips1

ubuntu/linux-azure-fips<5.15.0-1096.105+fips1

5.15.0-1096.105+fips1

ubuntu/linux-fips<5.15.0-156.166+fips1

5.15.0-156.166+fips1

ubuntu/linux-gcp-fips<5.15.0-1092.101+fips1

5.15.0-1092.101+fips1

ubuntu/linux<6.8.0-100.100

6.8.0-100.100

ubuntu/linux-aws<6.8.0-1046.49

6.8.0-1046.49

ubuntu/linux-aws-6.14<6.14.0-1015.15~24.04.1

6.14.0-1015.15~24.04.1

ubuntu/linux-azure<6.8.0-1046.52

6.8.0-1046.52

ubuntu/linux-azure-6.11*

ubuntu/linux-azure-6.14<6.14.0-1014.14~24.04.1

6.14.0-1014.14~24.04.1

ubuntu/linux-azure-fde<6.8.0-1046.53

6.8.0-1046.53

ubuntu/linux-azure-nvidia<6.8.0-1039.42

6.8.0-1039.42

ubuntu/linux-azure-nvidia-6.14<6.14.0-1007.7

6.14.0-1007.7

ubuntu/linux-gcp<6.8.0-1047.50

6.8.0-1047.50

ubuntu/linux-gcp-6.11*

ubuntu/linux-gcp-6.14<6.14.0-1018.19~24.04.1

6.14.0-1018.19~24.04.1

ubuntu/linux-gke<6.8.0-1043.48

6.8.0-1043.48

ubuntu/linux-gkeop<6.8.0-1030.33

6.8.0-1030.33

ubuntu/linux-hwe-6.11*

ubuntu/linux-ibm<6.8.0-1044.44

6.8.0-1044.44

ubuntu/linux-intel*

ubuntu/linux-lowlatency<6.8.0-100.100.1

6.8.0-100.100.1

ubuntu/linux-lowlatency-hwe-6.11*

ubuntu/linux-nvidia<6.8.0-1046.49

6.8.0-1046.49

ubuntu/linux-nvidia-6.11*

ubuntu/linux-nvidia-lowlatency<6.8.0-1046.49.1

6.8.0-1046.49.1

ubuntu/linux-nvidia-tegra<6.8.0-1020.20

6.8.0-1020.20

ubuntu/linux-oem-6.11*

ubuntu/linux-oem-6.14<6.14.0-1014.14

6.14.0-1014.14

ubuntu/linux-oem-6.8*

ubuntu/linux-oracle<6.8.0-1043.44

6.8.0-1043.44

ubuntu/linux-oracle-6.14<6.14.0-1015.15~24.04.1

6.14.0-1015.15~24.04.1

ubuntu/linux-raspi<6.8.0-1047.51

6.8.0-1047.51

ubuntu/linux-raspi-realtime*

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-6.14<6.14.0-34.34.1~24.04.1

6.14.0-34.34.1~24.04.1

ubuntu/linux-xilinx<6.8.0-1023.24

6.8.0-1023.24

ubuntu/linux-bluefield<6.8.0-1016.20

6.8.0-1016.20

ubuntu/linux-raspi-realtime<6.8.0-2037.38

6.8.0-2037.38

ubuntu/linux-realtime<6.8.1-1041.42

6.8.1-1041.42

ubuntu/linux-realtime-6.14<6.14.0-1014.14~24.04.1

6.14.0-1014.14~24.04.1

ubuntu/linux-aws-fips<6.8.0-1046.49+fips1

6.8.0-1046.49+fips1

ubuntu/linux-azure-fips<6.8.0-1046.52+fips1

6.8.0-1046.52+fips1

ubuntu/linux-fips<6.8.0-100.100+fips1

6.8.0-100.100+fips1

ubuntu/linux-gcp-fips<6.8.0-1047.50+fips1

6.8.0-1047.50+fips1

ubuntu/linux-azure-fde*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1092.99~20.04.1
Upgrade
Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1096.105~20.04.1
Upgrade
Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1092.101~20.04.1
Upgrade
Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-156.166~20.04.1
Upgrade
Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1086.89~20.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1087.93~20.04.1
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-156.166~20.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1045.45~20.04.1
Upgrade
Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1090.96~20.04.1
Upgrade
Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1087.91~20.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 5.15.0-156.166
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 5.15.0-1092.99
Upgrade
Upgrade ubuntu/linux-aws-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1046.49~22.04.1
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 5.15.0-1096.105
Upgrade
Upgrade ubuntu/linux-azure-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1051.57~22.04.1
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 5.15.0-1096.105.1
Upgrade
Upgrade ubuntu/linux-azure-fde-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1046.53~22.04.1
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 5.15.0-1092.101
Upgrade
Upgrade ubuntu/linux-gcp-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1047.50~22.04.2
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 5.15.0-1089.95
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 5.15.0-1075.83
Upgrade
Upgrade ubuntu/linux-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-100.100~22.04.1
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 5.15.0-1086.89
Upgrade
Upgrade ubuntu/linux-ibm-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1044.44~22.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.
Fixed in 5.15.0-1087.93
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 5.15.0-1088.93
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 5.15.0-156.166
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-100.100.1~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 5.15.0-1087.88
Upgrade
Upgrade ubuntu/linux-nvidia-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1046.49~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 5.15.0-1045.45
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-igx to a version that resolves this vulnerability.
Fixed in 5.15.0-1034.34
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 5.15.0-1090.96
Upgrade
Upgrade ubuntu/linux-oracle-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1043.44~22.04.1
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 5.15.0-1086.89
Upgrade
Upgrade ubuntu/linux-riscv-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-100.100~22.04.1
Upgrade
Upgrade ubuntu/linux-xilinx-zynqmp to a version that resolves this vulnerability.
Fixed in 5.15.0-1056.60
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 5.15.0-1076.78
Upgrade
Upgrade ubuntu/linux-intel-iot-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1085.87
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1092.101
Upgrade
Upgrade ubuntu/linux-realtime-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.1-1041.42~22.04.1
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1092.99+fips1
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1096.105+fips1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-156.166+fips1
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Fixed in 5.15.0-1092.101+fips1
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Fixed in 6.8.0-100.100
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Fixed in 6.8.0-1046.49
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Fixed in 6.14.0-1015.15~24.04.1
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Fixed in 6.8.0-1046.52
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Fixed in 6.14.0-1014.14~24.04.1
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Fixed in 6.8.0-1046.53
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Fixed in 6.8.0-1039.42
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Fixed in 6.14.0-1007.7
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Fixed in 6.8.0-1047.50
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Fixed in 6.14.0-1018.19~24.04.1
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Fixed in 6.8.0-1043.48
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Fixed in 6.8.0-1030.33
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Fixed in 6.8.0-1044.44
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Fixed in 6.8.0-100.100.1
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Fixed in 6.8.0-1046.49
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Fixed in 6.8.0-1046.49.1
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Fixed in 6.8.0-1020.20
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Fixed in 6.14.0-1014.14
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Fixed in 6.8.0-1043.44
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Fixed in 6.14.0-1015.15~24.04.1
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Fixed in 6.8.0-1047.51
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Fixed in 6.14.0-34.34.1~24.04.1
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Fixed in 6.8.0-1023.24
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Fixed in 6.8.0-1016.20
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Fixed in 6.8.0-2037.38
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Fixed in 6.8.1-1041.42
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Fixed in 6.14.0-1014.14~24.04.1
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Fixed in 6.8.0-1046.49+fips1
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Fixed in 6.8.0-1046.52+fips1
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Fixed in 6.8.0-100.100+fips1
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Fixed in 6.8.0-1047.50+fips1

Event History

Jul 4, 2025

CVE Published

via OSV·02:15 PM

Data Sourced

via OSV·02:15 PM

DescriptionSeverityAffected Software

Frequently Asked Questions

Which systems are most relevant to this issue?

The issue affects the listed Ubuntu Linux kernel packages, including linux, linux-aws-fips, linux-azure-fips, linux-fips, linux-gcp-fips, linux-azure, linux-gcp, and linux-oracle. The vulnerable path involves CALIPSO option handling together with TCP SYN Cookie processing.

What does an attacker need to exploit it?

The severity vector indicates network reachability, low attack complexity, no required privileges, and no user interaction. The failure occurs when CALIPSO request attribute handling encounters a request socket whose listener is NULL in the SYN Cookie case.

What is the security impact?

The reported flaw is a NULL-pointer dereference during CALIPSO option allocation. The provided vector rates availability impact as high and does not indicate confidentiality or integrity impact.

How is the issue addressed?

The fix makes calipso_req_setattr() and calipso_req_delattr() return an error when the SYN Cookie case has no listener socket, rather than dereferencing the NULL socket pointer.

UBUNTU-CVE-2025-38181: High severity ubuntu/linux-azure vulnerability

Affected Software

Remediation

Event History

Frequently Asked Questions

Which systems are most relevant to this issue?

What does an attacker need to exploit it?

What is the security impact?

How is the issue addressed?

Company

Resources

Contact

Frequently Asked Questions

Which systems are most relevant to this issue?

What does an attacker need to exploit it?

What is the security impact?

How is the issue addressed?