Bottlerocket: kernel-6.1: security update to 2.3.0

medium Tenable Self-Hosted Container Security Plugin ID 427946

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

- In the Linux kernel, the following vulnerability has been resolved: bpf: Fix overrunning reservations in
ringbuf The BPF ring buffer internally is implemented as a power-of-2 sized circular buffer, with two
logical and ever-increasing counters: consumer_pos is the consumer counter to show which logical position
the consumer consumed the data, and producer_pos which is the producer counter denoting the amount of data
reserved by all producers. Each time a record is reserved, the producer that "owns" the record will
successfully advance producer counter. In user space each time a record is read, the consumer of the data
advanced the consumer counter once it finished processing. Both counters are stored in separate pages so
that from user space, the producer counter is read-only and the consumer counter is read-write. One aspect
that simplifies and thus speeds up the implementation of both producers and consumers is how the data area
is mapped twice contiguously back-to-back in the virtual memory, allowing to not take any special measures
for samples that have to wrap around at the end of the circular buffer data area, because the next page
after the last data page would be first data page again, and thus the sample will still appear completely
contiguous in virtual memory. Each record has a struct bpf_ringbuf_hdr { u32 len; u32 pg_off; } header for
book-keeping the length and offset, and is inaccessible to the BPF program. Helpers like
bpf_ringbuf_reserve() return `(void *)hdr + BPF_RINGBUF_HDR_SZ` for the BPF program to use. Bing-Jhong and
Muhammad reported that it is however possible to make a second allocated memory chunk overlapping with the
first chunk and as a result, the BPF program is now able to edit first chunk's header. For example,
consider the creation of a BPF_MAP_TYPE_RINGBUF map with size of 0x4000. Next, the consumer_pos is
modified to 0x3000 /before/ a call to bpf_ringbuf_reserve() is made. This will allocate a chunk A, which
is in [0x0,0x3008], and the BPF program is able to edit [0x8,0x3008]. Now, lets allocate a chunk B with
size 0x3000. This will succeed because consumer_pos was edited ahead of time to pass the `new_prod_pos -
cons_pos > rb->mask` check. Chunk B will be in range [0x3008,0x6010], and the BPF program is able to edit
[0x3010,0x6010]. Due to the ring buffer memory layout mentioned earlier, the ranges [0x0,0x4000] and
[0x4000,0x8000] point to the same data pages. This means that chunk B at [0x4000,0x4008] is chunk A's
header. bpf_ringbuf_submit() / bpf_ringbuf_discard() use the header's pg_off to then locate the
bpf_ringbuf itself via bpf_ringbuf_restore_from_rec(). Once chunk B modified chunk A's header, then
bpf_ringbuf_commit() refers to the wrong page and could cause a crash. Fix it by calculating the oldest
pending_pos and check whether the range from the oldest outstanding record to the newest would span beyond
the ring buffer size. If that is the case, then reject the request. We've tested with the ring buffer
benchmark in BPF selftests (./benchs/run_bench_ringbufs.sh) before/after the fix and while it seems a bit
slower on some benchmarks, it is still not significantly enough to matter. (CVE-2024-41009)

Plugin Details

Severity: Medium

ID: 427946

Version: Revision 1.2

Type: Local

Family: Bottlerocket Local Security Checks

Published: 6/30/2025

Updated: 7/2/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.18

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

Vector: CVSS2#AV:L/AC:L/Au:S/C:N/I:N/A:C

CVSS Score Source: CVE-2024-41009

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 7/17/2024

Reference Information

CVE: CVE-2024-41009

Detections

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