UBUNTU-CVE-2026-74335: Null Pointer Dereference
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix NULL pointer dereference in bpftaskfromvpid() bpftaskfromvpid() looks up a task in the pid namespace of the current task, via findtaskbyvpid(): findtaskbyvpid(vpid) findtaskbypidns(vpid, taskactivepidns(current)) findpidns(nr, ns) -> idrfind(&ns->idr, nr) cgroupskb programs run in softirq, which may interrupt a task that is itself in doexit(). Once that task has passed exitnotify() -> releasetask() -> unhashprocess(), its threadpid is cleared, so taskactivepidns(current) returns NULL and findpidns() dereferences &NULL->idr: BUG: kernel NULL pointer dereference, address: 0000000000000050 RIP: 0010:idrfind+0x11/0x30 lib/idr.c:176 Call Trace: <IRQ> findpidns kernel/pid.c:370 [inline] findtaskbypidns+0x3b/0xe0 kernel/pid.c:485 bpftaskfromvpid+0x5b/0x200 kernel/bpf/helpers.c:2916 bpfprogrunarraycg+0x17e/0x530 kernel/bpf/cgroup.c:81 cgroupbpfrunfilterskb+0x12b/0x250 kernel/bpf/cgroup.c:1612 skfiltertrimcap+0x1dc/0x4c0 net/core/filter.c:148 tcpv4rcv+0x18d1/0x2200 net/ipv4/tcpipv4.c:2223 </IRQ> <TASK> doexit+0xa63/0x1270 kernel/exit.c:1010 getsignal+0x141c/0x1530 kernel/signal.c:3037 Bail out when current has no pid namespace.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-aws-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17~24.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-fde-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1016.16~24.04.1 - Upgrade
Upgrade
ubuntu/linux-gcp-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
Upgrade
ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38~24.04.4 - Upgrade
Upgrade
ubuntu/linux-nvidia-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1024.25~24.04.1 - Upgrade
Upgrade
ubuntu/linux-oracle-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1013.13~24.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1~24.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-38.38 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 7.0.0-1016.16 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 7.0.0-1008.9 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - Upgrade
Upgrade
ubuntu/linux-nvidia-bosto a version that resolves this vulnerability.Fixed in 7.0.0-2022.23 - Upgrade
Upgrade
ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1 - Compensating control
Update bpf_task_from_vpid() to bail out when the current task has no PID namespace, preventing find_pid_ns() from dereferencing a NULL namespace.
Event History
Frequently Asked Questions
Which deployments are most relevant to this issue?
The affected software list includes Ubuntu linux-riscv, linux-realtime, linux-hwe-edge, linux-azure, linux-gcp, linux-azure-fde, linux-gke, and linux-aws-5.0. The vulnerable path is specifically associated with cgroup_skb BPF programs.
What conditions are needed to trigger the fault?
A cgroup_skb BPF program must call bpf_task_from_vpid() while it runs in softirq context and interrupts a task that has progressed through exit handling far enough for its thread_pid to be cleared. That condition can cause task_active_pid_ns(current) to return NULL.
How can administrators recognize this failure?
The reported symptom is a kernel NULL pointer dereference in idr_find(), reached through find_pid_ns(), find_task_by_pid_ns(), and bpf_task_from_vpid(). The supplied call trace also includes cgroup BPF filtering functions such as bpf_prog_run_array_cg and __cgroup_bpf_run_filter_skb.