dellink() twice for the same device during
->exit_batch_rtnl().
Say we have two netns A & B and gtp device B that resides in netns B but
whose UDP socket is in netns A.
1. cleanup_net() processes netns A and then B.
2. gtp_net_exit_batch_rtnl() finds the device B while iterating
netns A's gn->gtp_dev_list and calls ->dellink().
[ device B is not yet unlinked from netns B
as unregister_netdevice_many() has not been called. ]
3. gtp_net_exit_batch_rtnl() finds the device B while iterating
netns B's for_each_netdev() and calls ->dellink().
gtp_dellink() cleans up the device's hash table, unlinks the dev from
gn->gtp_dev_list, and calls unregister_netdevice_queue().
Basically, calling gtp_dellink() multiple times is fine unless
CONFIG_DEBUG_LIST is enabled.
Let's remove for_each_netdev() in gtp_net_exit_batch_rtnl() and
delegate the destruction to default_device_exit_batch() as done
in bareudp.
[0]:
list_del corruption, ffff8880aaa62c00->next (autoslab_size_M_dev_P_net_core_dev_11127_8_1328_8_S_4096_A_64_n_139+0xc00/0x1000 [slab object]) is LIST_POISON1 (ffffffffffffff02) (prev is 0xffffffffffffff04)
kernel BUG at lib/list_debug.c:58!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 UID: 0 PID: 1804 Comm: kworker/u8:7 Tainted: G T 6.12.13-grsec-full-20250211091339 #1
Tainted: [T]=RANDSTRUCT
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Workqueue: netns cleanup_net
RIP: 0010:[ The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. This metric reflects the context by which vulnerability exploitation is possible. Local The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Low Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component. This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. Low The attacker 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 has the ability to access only non-sensitive resources. This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component. None The vulnerable system can be exploited without interaction from any user. The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope. Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs. 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. The Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve. This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. None There is no loss of confidentiality within the impacted component. This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. None There is no loss of integrity within the impacted component. This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. High There is a 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). The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability. These metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability. Linux>>Linux_kernel >> Version From (including) 6.1.127 To (excluding) 6.1.130 Linux>>Linux_kernel >> Version From (including) 6.6.74 To (excluding) 6.6.80 Linux>>Linux_kernel >> Version From (including) 6.12.11 To (excluding) 6.12.17 Linux>>Linux_kernel >> Version From (including) 6.13 To (excluding) 6.13.5 Linux>>Linux_kernel >> Version 5.4.290 Linux>>Linux_kernel >> Version 5.10.234 Linux>>Linux_kernel >> Version 5.15.177 Linux>>Linux_kernel >> Version 6.14 Linux>>Linux_kernel >> Version 6.14 Linux>>Linux_kernel >> Version 6.14CVE-2025-21865
Descriptions du CVE
gtp: Suppress list corruption splat in gtp_net_exit_batch_rtnl().
In the Linux kernel, the following vulnerability has been resolved:
gtp: Suppress list corruption splat in gtp_net_exit_batch_rtnl().
Brad Spengler reported the list_del() corruption splat in
gtp_net_exit_batch_rtnl(). [0]
Commit eb28fd76c0a0 ("gtp: Destroy device along with udp socket's netns
dismantle.") added the for_each_netdev() loop in gtp_net_exit_batch_rtnl()
to destroy devices in each netns as done in geneve and ip tunnels.
However, this could trigger ->dellink() twice for the same device during
->exit_batch_rtnl().
Say we have two netns A & B and gtp device B that resides in netns B but
whose UDP socket is in netns A.
1. cleanup_net() processes netns A and then B.
2. gtp_net_exit_batch_rtnl() finds the device B while iterating
netns A's gn->gtp_dev_list and calls ->dellink().
[ device B is not yet unlinked from netns B
as unregister_netdevice_many() has not been called. ]
3. gtp_net_exit_batch_rtnl() finds the device B while iterating
netns B's for_each_netdev() and calls ->dellink().
gtp_dellink() cleans up the device's hash table, unlinks the dev from
gn->gtp_dev_list, and calls unregister_netdevice_queue().
Basically, calling gtp_dellink() multiple times is fine unless
CONFIG_DEBUG_LIST is enabled.
Let's remove for_each_netdev() in gtp_net_exit_batch_rtnl() and
delegate the destruction to default_device_exit_batch() as done
in bareudp.
[0]:
list_del corruption, ffff8880aaa62c00->next (autoslab_size_M_dev_P_net_core_dev_11127_8_1328_8_S_4096_A_64_n_139+0xc00/0x1000 [slab object]) is LIST_POISON1 (ffffffffffffff02) (prev is 0xffffffffffffff04)
kernel BUG at lib/list_debug.c:58!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 UID: 0 PID: 1804 Comm: kworker/u8:7 Tainted: G T 6.12.13-grsec-full-20250211091339 #1
Tainted: [T]=RANDSTRUCT
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Workqueue: netns cleanup_net
RIP: 0010:[Informations du CVE
Faiblesses connexes
Nom de la faiblesse
Source
Out-of-bounds Write
The product writes data past the end, or before the beginning, of the intended buffer.
Métriques
Métriques
Score
Gravité
CVSS Vecteur
Source
V3.1
5.5
MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Base: Exploitabilty Metrics
Base: Scope Metrics
Base: Impact Metrics
Temporal Metrics
Environmental Metrics
[email protected]
EPSS
Score EPSS
Percentile EPSS
Products Mentioned
Configuraton 0
Références