CVE-2024-58088

CVE-2024-58088

Título es
CVE-2024-58088

Mié, 12/03/2025 – 10:15

Gravedad 2.0 Txt
Pendiente de análisis

Título en

CVE-2024-58088

Descripción en
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.

12/03/2025

12/03/2025

Gravedad 3.1 Txt Gravedad 3.1 (CVSS 3.1 Base Score)
Pendiente de análisis

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