bpf: Fix oob access in cgroup local storage
Lonial reported that an out-of-bounds access in cgroup local storage
can be crafted via tail calls. Given two programs each utilizing a
cgroup local storage with a different value size, and one program
doing a tail call into the other. The verifier will validate each of
the indivial programs just fine. However, in the runtime context
the bpf_cg_run_ctx holds an bpf_prog_array_item which contains the
BPF program as well as any cgroup local storage flavor the program
uses. Helpers such as bpf_get_local_storage() pick this up from the
runtime context:
ctx = container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx);
storage = ctx->prog_item->cgroup_storage[stype];
if (stype == BPF_CGROUP_STORAGE_SHARED)
ptr = &READ_ONCE(storage->buf)->data[0];
else
ptr = this_cpu_ptr(storage->percpu_buf);
For the second program which was called from the originally attached
one, this means bpf_get_local_storage() will pick up the former
program's map, not its own. With mismatching sizes, this can result
in an unintended out-of-bounds access.
To fix this issue, we need to extend bpf_map_owner with an array of
storage_cookie[] to match on i) the exact maps from the original
program if the second program was using bpf_get_local_storage(), or
ii) allow the tail call combination if the second program was not
using any of the cgroup local storage maps.
No analysis available yet.
No remediation available yet.
Tracking
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| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-4328-1 | linux-6.1 security update |
Debian DSA |
DSA-6008-1 | linux security update |
Debian DSA |
DSA-6009-1 | linux security update |
EUVD |
EUVD-2025-25076 | In the Linux kernel, the following vulnerability has been resolved: bpf: Fix oob access in cgroup local storage Lonial reported that an out-of-bounds access in cgroup local storage can be crafted via tail calls. Given two programs each utilizing a cgroup local storage with a different value size, and one program doing a tail call into the other. The verifier will validate each of the indivial programs just fine. However, in the runtime context the bpf_cg_run_ctx holds an bpf_prog_array_item which contains the BPF program as well as any cgroup local storage flavor the program uses. Helpers such as bpf_get_local_storage() pick this up from the runtime context: ctx = container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx); storage = ctx->prog_item->cgroup_storage[stype]; if (stype == BPF_CGROUP_STORAGE_SHARED) ptr = &READ_ONCE(storage->buf)->data[0]; else ptr = this_cpu_ptr(storage->percpu_buf); For the second program which was called from the originally attached one, this means bpf_get_local_storage() will pick up the former program's map, not its own. With mismatching sizes, this can result in an unintended out-of-bounds access. To fix this issue, we need to extend bpf_map_owner with an array of storage_cookie[] to match on i) the exact maps from the original program if the second program was using bpf_get_local_storage(), or ii) allow the tail call combination if the second program was not using any of the cgroup local storage maps. |
Ubuntu USN |
USN-7909-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7909-2 | Linux kernel (Real-time) vulnerabilities |
Ubuntu USN |
USN-7909-3 | Linux kernel (FIPS) vulnerabilities |
Ubuntu USN |
USN-7910-1 | Linux kernel (Azure FIPS) vulnerabilities |
Ubuntu USN |
USN-7909-4 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7910-2 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-7909-5 | Linux kernel (Raspberry Pi) vulnerabilities |
Ubuntu USN |
USN-7933-1 | Linux kernel (KVM) vulnerabilities |
Ubuntu USN |
USN-7938-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-8095-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8095-2 | Linux kernel (FIPS) vulnerabilities |
Ubuntu USN |
USN-8100-1 | Linux kernel (NVIDIA) vulnerabilities |
Ubuntu USN |
USN-8095-3 | Linux kernel (Real-time) vulnerabilities |
Ubuntu USN |
USN-8095-4 | Linux kernel (AWS) vulnerabilities |
Ubuntu USN |
USN-8125-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-8126-1 | Linux kernel (Azure) vulnerabilities |
Wed, 07 Jan 2026 16:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Debian
Debian debian Linux |
|
| CPEs | cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
|
| Vendors & Products |
Debian
Debian debian Linux |
|
| Metrics |
cvssV3_1
|
cvssV3_1
|
Mon, 03 Nov 2025 18:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Tue, 09 Sep 2025 17:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Mon, 18 Aug 2025 21:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Vendors & Products |
Linux
Linux linux Kernel |
Mon, 18 Aug 2025 12:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-125 | |
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Sat, 16 Aug 2025 09:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: bpf: Fix oob access in cgroup local storage Lonial reported that an out-of-bounds access in cgroup local storage can be crafted via tail calls. Given two programs each utilizing a cgroup local storage with a different value size, and one program doing a tail call into the other. The verifier will validate each of the indivial programs just fine. However, in the runtime context the bpf_cg_run_ctx holds an bpf_prog_array_item which contains the BPF program as well as any cgroup local storage flavor the program uses. Helpers such as bpf_get_local_storage() pick this up from the runtime context: ctx = container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx); storage = ctx->prog_item->cgroup_storage[stype]; if (stype == BPF_CGROUP_STORAGE_SHARED) ptr = &READ_ONCE(storage->buf)->data[0]; else ptr = this_cpu_ptr(storage->percpu_buf); For the second program which was called from the originally attached one, this means bpf_get_local_storage() will pick up the former program's map, not its own. With mismatching sizes, this can result in an unintended out-of-bounds access. To fix this issue, we need to extend bpf_map_owner with an array of storage_cookie[] to match on i) the exact maps from the original program if the second program was using bpf_get_local_storage(), or ii) allow the tail call combination if the second program was not using any of the cgroup local storage maps. | |
| Title | bpf: Fix oob access in cgroup local storage | |
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-11-03T17:39:11.518Z
Reserved: 2025-04-16T04:51:24.022Z
Link: CVE-2025-38502
No data.
Status : Analyzed
Published: 2025-08-16T10:15:25.653
Modified: 2026-01-07T16:32:00.363
Link: CVE-2025-38502
OpenCVE Enrichment
Updated: 2025-08-18T20:50:00Z
Debian DLA
Debian DSA
EUVD
Ubuntu USN