UBUNTU-CVE-2025-40027: Race Condition

Q: Who can realistically trigger this issue?

Exploitation requires local access with low privileges. The affected code path is associated with mounting a 9P/v9fs filesystem, so systems where untrusted local users can initiate or influence 9P mounts are the relevant exposure scenario.

Q: What is the likely security impact if exploited?

The supplied severity vector rates confidentiality, integrity, and availability impacts as high. The underlying flaw is a race condition involving a double request release in the kernel's 9P file-descriptor transport cancellation path.

Q: Which Ubuntu kernel packages are listed as affected?

The listed software includes ubuntu/linux, ubuntu/linux-aws, ubuntu/linux-azure, ubuntu/linux-gcp, ubuntu/linux-fips, ubuntu/linux-aws-fips, ubuntu/linux-azure-fips, and ubuntu/linux-gcp-fips. No fixed package versions are provided in the supplied data.

Published Oct 28, 2025

Updated

In the Linux kernel, the following vulnerability has been resolved: net/9p: fix double req put in p9fdcancelled Syzkaller reports a KASAN issue as below: general protection fault, probably for non-canonical address 0xfbd59c0000000021: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: maybe wild-memory-access in range [0xdead000000000108-0xdead00000000010f] CPU: 0 PID: 5083 Comm: syz-executor.2 Not tainted 6.1.134-syzkaller-00037-g855bd1d7d838 #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:listdel include/linux/list.h:114 [inline] RIP: 0010:listdelentry include/linux/list.h:137 [inline] RIP: 0010:listdel include/linux/list.h:148 [inline] RIP: 0010:p9fdcancelled+0xe9/0x200 net/9p/transfd.c:734 Call Trace: <TASK> p9clientflush+0x351/0x440 net/9p/client.c:614 p9clientrpc+0xb6b/0xc70 net/9p/client.c:734 p9clientversion net/9p/client.c:920 [inline] p9clientcreate+0xb51/0x1240 net/9p/client.c:1027 v9fssessioninit+0x1f0/0x18f0 fs/9p/v9fs.c:408 v9fsmount+0xba/0xcb0 fs/9p/vfssuper.c:126 legacygettree+0x108/0x220 fs/fscontext.c:632 vfsgettree+0x8e/0x300 fs/super.c:1573 donewmount fs/namespace.c:3056 [inline] pathmount+0x6a6/0x1e90 fs/namespace.c:3386 domount fs/namespace.c:3399 [inline] dosysmount fs/namespace.c:3607 [inline] sesysmount fs/namespace.c:3584 [inline] x64sysmount+0x283/0x300 fs/namespace.c:3584 dosyscallx64 arch/x86/entry/common.c:51 [inline] dosyscall64+0x35/0x80 arch/x86/entry/common.c:81 entrySYSCALL64afterhwframe+0x6e/0xd8 This happens because of a race condition between: - The 9p client sending an invalid flush request and later cleaning it up; - The 9p client in p9readwork() canceled all pending requests. Thread 1 Thread 2 ... p9clientcreate() ... p9fdcreate() ... p9conncreate() ... // start Thread 2 INITWORK(&m->rq, p9readwork); p9readwork() ... p9clientrpc() ... ... p9conncancel() ... spinlock(&m->reqlock); ... p9fdcancelled() ... ... spinunlock(&m->reqlock); // status rewrite p9clientcb(m->client, req, REQSTATUSERROR) // first remove listdel(&req->reqlist); ... spinlock(&m->reqlock) ... // second remove listdel(&req->reqlist); spinunlock(&m->reqlock) ... Commit 74d6a5d56629 ("9p/transfd: Fix concurrency del of reqlist in p9fdcancelled/p9readwork") fixes a concurrency issue in the 9p filesystem client where the reqlist could be deleted simultaneously by both p9readwork and p9fdcancelled functions, but for the case where req->status equals REQSTATUSRCVD. Update the check for req->status in p9fdcancelled to skip processing not just received requests, but anything that is not SENT, as whatever changed the state from SENT also removed the request from its list. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. [updated the check from status == RECV || status == ERROR to status != SENT]

Affected Software

233 affected componentsFixes available

ubuntu/linux-aws*

ubuntu/linux-azure*

ubuntu/linux-lts-xenial*

ubuntu/linux*

ubuntu/linux-aws*

ubuntu/linux-aws-hwe*

ubuntu/linux-azure*

ubuntu/linux-gcp*

ubuntu/linux-hwe*

ubuntu/linux-hwe-edge*

ubuntu/linux-kvm*

ubuntu/linux-oracle*

ubuntu/linux-fips*

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<5.15.0-1100.107~20.04.2

5.15.0-1100.107~20.04.2

ubuntu/linux-aws-5.8*

ubuntu/linux-azure*

ubuntu/linux-azure-5.11*

ubuntu/linux-azure-5.13*

ubuntu/linux-azure-5.15<5.15.0-1110.119~20.04.1

5.15.0-1110.119~20.04.1

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<5.15.0-1100.109~20.04.1

5.15.0-1100.109~20.04.1

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<5.15.0-170.180~20.04.3

5.15.0-170.180~20.04.3

ubuntu/linux-hwe-5.8*

ubuntu/linux-ibm*

ubuntu/linux-ibm-5.15<5.15.0-1094.97~20.04.1

5.15.0-1094.97~20.04.1

ubuntu/linux-intel-5.13*

ubuntu/linux-intel-iotg-5.15<5.15.0-1095.101~20.04.1

5.15.0-1095.101~20.04.1

ubuntu/linux-iot*

ubuntu/linux-kvm*

ubuntu/linux-lowlatency-hwe-5.15<5.15.0-170.180~20.04.1

5.15.0-170.180~20.04.1

ubuntu/linux-nvidia-tegra-5.15<5.15.0-1052.52~20.04.2

5.15.0-1052.52~20.04.2

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<5.15.0-1097.103~20.04.1

5.15.0-1097.103~20.04.1

ubuntu/linux-oracle-5.8*

ubuntu/linux-raspi*

ubuntu/linux-raspi2*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.11*

ubuntu/linux-riscv-5.15<5.15.0-1095.99~20.04.1

5.15.0-1095.99~20.04.1

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<5.15.0-170.180

5.15.0-170.180

ubuntu/linux-allwinner-5.19*

ubuntu/linux-aws<5.15.0-1100.107

5.15.0-1100.107

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-aws-6.5*

ubuntu/linux-aws-6.8<6.8.0-1050.53~22.04.1

6.8.0-1050.53~22.04.1

ubuntu/linux-azure<5.15.0-1109.118

5.15.0-1109.118

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<5.15.0-1109.118.1

5.15.0-1109.118.1

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-azure-fde-6.8<6.8.0-1058.65~22.04.1

6.8.0-1058.65~22.04.1

ubuntu/linux-gcp<5.15.0-1100.109

5.15.0-1100.109

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-gcp-6.5*

ubuntu/linux-gcp-6.8<6.8.0-1052.55~22.04.1

6.8.0-1052.55~22.04.1

ubuntu/linux-gke<5.15.0-1096.102

5.15.0-1096.102

ubuntu/linux-gkeop<5.15.0-1083.91

5.15.0-1083.91

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-hwe-6.5*

ubuntu/linux-hwe-6.8<6.8.0-106.106~22.04.1

6.8.0-106.106~22.04.1

ubuntu/linux-ibm<5.15.0-1094.97

5.15.0-1094.97

ubuntu/linux-ibm-6.8<6.8.0-1049.49~22.04.1

6.8.0-1049.49~22.04.1

ubuntu/linux-intel-iot-realtime*

ubuntu/linux-intel-iotg<5.15.0-1095.101

5.15.0-1095.101

ubuntu/linux-kvm<5.15.0-1092.97

5.15.0-1092.97

ubuntu/linux-lowlatency<5.15.0-170.180

5.15.0-170.180

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-lowlatency-hwe-6.5*

ubuntu/linux-lowlatency-hwe-6.8<6.8.0-106.106.1~22.04.1

6.8.0-106.106.1~22.04.1

ubuntu/linux-nvidia<5.15.0-1095.96

5.15.0-1095.96

ubuntu/linux-nvidia-6.2*

ubuntu/linux-nvidia-6.5*

ubuntu/linux-nvidia-6.8<6.8.0-1049.52~22.04.1

6.8.0-1049.52~22.04.1

ubuntu/linux-nvidia-tegra<5.15.0-1052.52

5.15.0-1052.52

ubuntu/linux-nvidia-tegra-igx<5.15.0-1041.41

5.15.0-1041.41

ubuntu/linux-oem-5.17*

ubuntu/linux-oem-6.0*

ubuntu/linux-oem-6.1*

ubuntu/linux-oem-6.5*

ubuntu/linux-oracle<5.15.0-1097.103

5.15.0-1097.103

ubuntu/linux-oracle-6.5*

ubuntu/linux-oracle-6.8<6.8.0-1047.48~22.04.1

6.8.0-1047.48~22.04.1

ubuntu/linux-raspi<5.15.0-1097.100

5.15.0-1097.100

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-riscv-6.5*

ubuntu/linux-riscv-6.8<6.8.0-106.106~22.04.1

6.8.0-106.106~22.04.1

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-starfive-6.5*

ubuntu/linux-xilinx-zynqmp<5.15.0-1064.68

5.15.0-1064.68

ubuntu/linux-bluefield<5.15.0-1084.86

5.15.0-1084.86

ubuntu/linux-intel-iot-realtime<5.15.0-1092.94

5.15.0-1092.94

ubuntu/linux-realtime<5.15.0-1099.108

5.15.0-1099.108

ubuntu/linux-realtime-6.8<6.8.1-1045.46~22.04.1

6.8.1-1045.46~22.04.1

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips<5.15.0-1100.107+fips1

5.15.0-1100.107+fips1

ubuntu/linux-azure-fips<5.15.0-1109.118+fips1

5.15.0-1109.118+fips1

ubuntu/linux-fips<5.15.0-170.180+fips1

5.15.0-170.180+fips1

ubuntu/linux-gcp-fips<5.15.0-1100.109+fips1

5.15.0-1100.109+fips1

ubuntu/linux<6.8.0-106.106

6.8.0-106.106

ubuntu/linux-aws<6.8.0-1050.53

6.8.0-1050.53

ubuntu/linux-aws-6.14*

ubuntu/linux-azure<6.8.0-1051.57

6.8.0-1051.57

ubuntu/linux-azure-6.11*

ubuntu/linux-azure-6.14*

ubuntu/linux-azure-fde<6.8.0-1058.65

6.8.0-1058.65

ubuntu/linux-azure-fde-6.14*

ubuntu/linux-azure-nvidia<6.8.0-1039.42

6.8.0-1039.42

ubuntu/linux-azure-nvidia-6.14*

ubuntu/linux-gcp<6.8.0-1052.55

6.8.0-1052.55

ubuntu/linux-gcp-6.11*

ubuntu/linux-gcp-6.14*

ubuntu/linux-gke<6.8.0-1048.53

6.8.0-1048.53

ubuntu/linux-gkeop<6.8.0-1035.38

6.8.0-1035.38

ubuntu/linux-hwe-6.11*

ubuntu/linux-hwe-6.14*

ubuntu/linux-ibm<6.8.0-1049.49

6.8.0-1049.49

ubuntu/linux-lowlatency<6.8.0-106.106.1

6.8.0-106.106.1

ubuntu/linux-lowlatency-hwe-6.11*

ubuntu/linux-nvidia<6.8.0-1049.52

6.8.0-1049.52

ubuntu/linux-nvidia-6.11*

ubuntu/linux-nvidia-lowlatency<6.8.0-1049.52.1

6.8.0-1049.52.1

ubuntu/linux-nvidia-tegra<6.8.0-1020.20

6.8.0-1020.20

ubuntu/linux-oem-6.11*

ubuntu/linux-oem-6.14*

ubuntu/linux-oem-6.17<6.17.0-1006.6

6.17.0-1006.6

ubuntu/linux-oem-6.8*

ubuntu/linux-oracle<6.8.0-1047.48

6.8.0-1047.48

ubuntu/linux-oracle-6.14*

ubuntu/linux-raspi<6.8.0-1050.54

6.8.0-1050.54

ubuntu/linux-raspi-realtime*

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-6.14*

ubuntu/linux-xilinx<6.8.0-1028.29

6.8.0-1028.29

ubuntu/linux-bluefield<6.8.0-1017.21

6.8.0-1017.21

ubuntu/linux-raspi-realtime<6.8.0-2040.41

6.8.0-2040.41

ubuntu/linux-realtime<6.8.1-1045.46

6.8.1-1045.46

ubuntu/linux-realtime-6.14*

ubuntu/linux-aws-fips<6.8.0-1050.53+fips1

6.8.0-1050.53+fips1

ubuntu/linux-azure-fips<6.8.0-1052.58+fips1

6.8.0-1052.58+fips1

ubuntu/linux-fips<6.8.0-106.106+fips1

6.8.0-106.106+fips1

ubuntu/linux-gcp-fips<6.8.0-1052.55+fips1

6.8.0-1052.55+fips1

ubuntu/linux<6.17.0-7.7

6.17.0-7.7

ubuntu/linux-aws<6.17.0-1004.4

6.17.0-1004.4

ubuntu/linux-azure<6.17.0-1006.6

6.17.0-1006.6

ubuntu/linux-azure-fde*

ubuntu/linux-gcp<6.17.0-1004.4

6.17.0-1004.4

ubuntu/linux-oracle<6.17.0-1005.5

6.17.0-1005.5

ubuntu/linux-raspi<6.17.0-1005.5

6.17.0-1005.5

ubuntu/linux-realtime<6.17.0-1003.4

6.17.0-1003.4

ubuntu/linux-riscv<6.17.0-7.7.1

6.17.0-7.7.1

ubuntu/linux-vmware*

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 5.15.0-1100.107~20.04.2
Upgrade
Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1110.119~20.04.1
Upgrade
Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1100.109~20.04.1
Upgrade
Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-170.180~20.04.3
Upgrade
Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1094.97~20.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1095.101~20.04.1
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-170.180~20.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1052.52~20.04.2
Upgrade
Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1097.103~20.04.1
Upgrade
Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1095.99~20.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 5.15.0-170.180
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 5.15.0-1100.107
Upgrade
Upgrade ubuntu/linux-aws-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1050.53~22.04.1
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 5.15.0-1109.118
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 5.15.0-1109.118.1
Upgrade
Upgrade ubuntu/linux-azure-fde-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1058.65~22.04.1
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 5.15.0-1100.109
Upgrade
Upgrade ubuntu/linux-gcp-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1052.55~22.04.1
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 5.15.0-1096.102
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 5.15.0-1083.91
Upgrade
Upgrade ubuntu/linux-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-106.106~22.04.1
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 5.15.0-1094.97
Upgrade
Upgrade ubuntu/linux-ibm-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1049.49~22.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.
Fixed in 5.15.0-1095.101
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 5.15.0-1092.97
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 5.15.0-170.180
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-106.106.1~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 5.15.0-1095.96
Upgrade
Upgrade ubuntu/linux-nvidia-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1049.52~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 5.15.0-1052.52
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-igx to a version that resolves this vulnerability.
Fixed in 5.15.0-1041.41
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Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 5.15.0-1097.103
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Upgrade ubuntu/linux-oracle-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1047.48~22.04.1
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 5.15.0-1097.100
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Upgrade ubuntu/linux-riscv-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-106.106~22.04.1
Upgrade
Upgrade ubuntu/linux-xilinx-zynqmp to a version that resolves this vulnerability.
Fixed in 5.15.0-1064.68
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 5.15.0-1084.86
Upgrade
Upgrade ubuntu/linux-intel-iot-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1092.94
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1099.108
Upgrade
Upgrade ubuntu/linux-realtime-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.1-1045.46~22.04.1
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1100.107+fips1
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1109.118+fips1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-170.180+fips1
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1100.109+fips1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 6.8.0-106.106
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 6.8.0-1050.53
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 6.8.0-1051.57
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 6.8.0-1058.65
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Upgrade ubuntu/linux-azure-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1039.42
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Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 6.8.0-1052.55
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Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 6.8.0-1048.53
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Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 6.8.0-1035.38
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Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 6.8.0-1049.49
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Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-106.106.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1049.52
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Fixed in 6.8.0-1049.52.1
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Fixed in 6.8.0-1020.20
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Fixed in 6.17.0-1006.6
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Fixed in 6.8.0-1047.48
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Fixed in 6.8.0-1050.54
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Fixed in 6.8.0-1028.29
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Fixed in 6.8.0-1017.21
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Fixed in 6.8.0-2040.41
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Fixed in 6.8.1-1045.46
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Fixed in 6.8.0-1050.53+fips1
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Fixed in 6.8.0-1052.58+fips1
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Fixed in 6.8.0-106.106+fips1
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Fixed in 6.8.0-1052.55+fips1
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Fixed in 6.17.0-7.7
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Fixed in 6.17.0-1004.4
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Fixed in 6.17.0-1006.6
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Fixed in 6.17.0-1004.4
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Fixed in 6.17.0-1005.5
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Fixed in 6.17.0-1005.5
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Fixed in 6.17.0-1003.4
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Fixed in 6.17.0-7.7.1
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Patch 74d6a5d56629

Event History

Oct 28, 2025

CVE Published

via OSV·10:15 AM

Data Sourced

via OSV·10:15 AM

DescriptionSeverityAffected Software

Frequently Asked Questions

Who can realistically trigger this issue?

Exploitation requires local access with low privileges. The affected code path is associated with mounting a 9P/v9fs filesystem, so systems where untrusted local users can initiate or influence 9P mounts are the relevant exposure scenario.

What is the likely security impact if exploited?

The supplied severity vector rates confidentiality, integrity, and availability impacts as high. The underlying flaw is a race condition involving a double request release in the kernel's 9P file-descriptor transport cancellation path.

Which Ubuntu kernel packages are listed as affected?

The listed software includes ubuntu/linux, ubuntu/linux-aws, ubuntu/linux-azure, ubuntu/linux-gcp, ubuntu/linux-fips, ubuntu/linux-aws-fips, ubuntu/linux-azure-fips, and ubuntu/linux-gcp-fips. No fixed package versions are provided in the supplied data.

UBUNTU-CVE-2025-40027: Race Condition

Affected Software

Remediation

Event History

Frequently Asked Questions

Who can realistically trigger this issue?

What is the likely security impact if exploited?

Which Ubuntu kernel packages are listed as affected?

Company

Resources

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Frequently Asked Questions

Who can realistically trigger this issue?

What is the likely security impact if exploited?

Which Ubuntu kernel packages are listed as affected?