CVE-2024-58088 in Linux
Summary
by MITRE • 03/12/2025
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix deadlock when freeing cgroup storage
The following commit bc235cdb423a ("bpf: Prevent deadlock from recursive bpf_task_storage_[get|delete]")
first introduced deadlock prevention for fentry/fexit programs attaching on bpf_task_storage helpers. That commit also employed the logic in map free path in its v6 version.
Later bpf_cgrp_storage was first introduced in c4bcfb38a95e ("bpf: Implement cgroup storage available to non-cgroup-attached bpf progs") which faces the same issue as bpf_task_storage, instead of its busy counter, NULL was passed to bpf_local_storage_map_free() which opened a window to cause deadlock:
(acquiring local_storage->lock) _raw_spin_lock_irqsave+0x3d/0x50 bpf_local_storage_update+0xd1/0x460 bpf_cgrp_storage_get+0x109/0x130 bpf_prog_a4d4a370ba857314_cgrp_ptr+0x139/0x170 ? __bpf_prog_enter_recur+0x16/0x80 bpf_trampoline_6442485186+0x43/0xa4 cgroup_storage_ptr+0x9/0x20 (holding local_storage->lock) bpf_selem_unlink_storage_nolock.constprop.0+0x135/0x160 bpf_selem_unlink_storage+0x6f/0x110 bpf_local_storage_map_free+0xa2/0x110 bpf_map_free_deferred+0x5b/0x90 process_one_work+0x17c/0x390 worker_thread+0x251/0x360 kthread+0xd2/0x100 ret_from_fork+0x34/0x50 ret_from_fork_asm+0x1a/0x30
Progs: - A: SEC("fentry/cgroup_storage_ptr") - cgid (BPF_MAP_TYPE_HASH) Record the id of the cgroup the current task belonging to in this hash map, using the address of the cgroup as the map key. - cgrpa (BPF_MAP_TYPE_CGRP_STORAGE) If current task is a kworker, lookup the above hash map using function parameter @owner as the key to get its corresponding cgroup id which is then used to get a trusted pointer to the cgroup through bpf_cgroup_from_id(). This trusted pointer can then be passed to bpf_cgrp_storage_get() to finally trigger the deadlock issue. - B: SEC("tp_btf/sys_enter") - cgrpb (BPF_MAP_TYPE_CGRP_STORAGE) The only purpose of this prog is to fill Prog A's hash map by calling bpf_cgrp_storage_get() for as many userspace tasks as possible.
Steps to reproduce: - Run A; - while (true) { Run B; Destroy B; }
Fix this issue by passing its busy counter to the free procedure so it can be properly incremented before storage/smap locking.
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Analysis
by VulDB Data Team • 12/14/2025
The vulnerability CVE-2024-58088 affects the Linux kernel and stems from a deadlock condition occurring during the freeing of cgroup storage in BPF (Berkeley Packet Filter) programs. This issue is rooted in the improper handling of synchronization primitives when BPF programs interact with cgroup storage maps, specifically in the context of recursive operations. The flaw manifests when BPF programs attempt to access or free cgroup storage while holding locks, leading to a circular dependency that halts execution. The problem was initially addressed in commit bc235cdb423a which introduced deadlock prevention for fentry/fexit programs attaching to bpf_task_storage helpers, but the fix did not extend to cgroup storage, leaving a similar vulnerability unaddressed.
BPF cgroup storage was introduced in commit c4bcfb38a95e and shares structural similarities with bpf_task_storage, particularly in how they manage local storage access. However, cgroup storage uses a different approach for tracking busy operations, passing NULL instead of a busy counter to the bpf_local_storage_map_free() function. This omission creates a window where concurrent access can lead to a deadlock situation, as demonstrated in the call trace showing acquisition of local_storage->lock followed by recursive locking attempts. The vulnerability is particularly severe because it can be triggered through legitimate BPF program execution patterns, making it a latent risk in systems that rely on BPF for monitoring or enforcement.
The operational impact of CVE-2024-58088 is significant for Linux systems utilizing BPF programs with cgroup storage, especially in environments where kernel-level monitoring or resource control is implemented. The deadlock condition can cause system hangs, leading to denial of service scenarios where the kernel becomes unresponsive to further operations. The vulnerability is especially concerning in high-throughput systems or those running complex BPF programs that frequently access cgroup storage, as the probability of triggering the deadlock increases with program complexity and concurrent access patterns. The issue affects the kernel's ability to properly manage BPF map lifecycles, potentially causing cascading failures in systems that depend on BPF for security or performance monitoring.
The fix for CVE-2024-58088 involves passing the busy counter to the map free procedure, ensuring that it is properly incremented before storage or smap locking occurs. This approach aligns with the principles of deadlock prevention established in prior patches and maintains consistency with how bpf_task_storage handles similar scenarios. The solution is consistent with the ATT&CK framework's concept of privilege escalation through kernel vulnerabilities, as the deadlock can be exploited to deny system services. Additionally, this fix addresses a CWE-367 weakness related to time-of-check to time-of-use vulnerabilities, as it prevents race conditions during resource cleanup. The mitigation ensures that proper synchronization is maintained during map freeing operations, preventing the recursive locking patterns that lead to the deadlock. This correction aligns with the broader security principle of avoiding circular dependencies in kernel locking mechanisms and maintaining atomicity in resource management operations.