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Echo: linux: security update to 6.1.176-1

high Tenable Self-Hosted Container Security Plugin ID 464781

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: net: stmmac: Prevent NULL deref when
 RX memory exhausted The CPU receives frames from the MAC through conventional DMA: the CPU allocates
 buffers for the MAC, then the MAC fills them and returns ownership to the CPU. For each hardware RX queue,
 the CPU and MAC coordinate through a shared ring array of DMA descriptors: one descriptor per DMA buffer.
 Each descriptor includes the buffer's physical address and a status flag ("OWN") indicating which side
 owns the buffer: OWN=0 for CPU, OWN=1 for MAC. The CPU is only allowed to set the flag and the MAC is only
 allowed to clear it, and both must move through the ring in sequence: thus the ring is used for both
 "submissions" and "completions." In the stmmac driver, stmmac_rx() bookmarks its position in the ring with
 the `cur_rx` index. The main receive loop in that function checks for rx_descs[cur_rx].own=0, gives the
 corresponding buffer to the network stack (NULLing the pointer), and increments `cur_rx` modulo the ring
 size. After the loop exits, stmmac_rx_refill(), which bookmarks its position with `dirty_rx`, allocates
 fresh buffers and rearms the descriptors (setting OWN=1). If it fails any allocation, it simply stops
 early (leaving OWN=0) and will retry where it left off when next called. This means descriptors have a
 three-stage lifecycle (terms my own): - `empty` (OWN=1, buffer valid) - `full` (OWN=0, buffer valid and
 populated) - `dirty` (OWN=0, buffer NULL) But because stmmac_rx() only checks OWN, it confuses
 `full`/`dirty`. In the past (see 'Fixes:'), there was a bug where the loop could cycle `cur_rx` all the
 way back to the first descriptor it dirtied, resulting in a NULL dereference when mistaken for `full`. The
 aforementioned commit resolved that *specific* failure by capping the loop's iteration limit at
 `dma_rx_size - 1`, but this is only a partial fix: if the previous stmmac_rx_refill() didn't complete,
 then there are leftover `dirty` descriptors that the loop might encounter without needing to cycle fully
 around. The current code therefore panics (see 'Closes:') when stmmac_rx_refill() is memory-starved long
 enough for `cur_rx` to catch up to `dirty_rx`. Fix this by explicitly checking, before advancing `cur_rx`,
 if the next entry is dirty; exit the loop if so. This prevents processing of the final, used descriptor
 until stmmac_rx_refill() succeeds, but fully prevents the `cur_rx == dirty_rx` ambiguity as the previous
 bugfix intended: so remove the clamp as well. Since stmmac_rx_zc() is a copy-paste-and-tweak of
 stmmac_rx() and the code structure is identical, any fix to stmmac_rx() will also need a corresponding fix
 for stmmac_rx_zc(). Therefore, apply the same check there. In stmmac_rx() (not stmmac_rx_zc()), a related
 bug remains: after the MAC sets OWN=0 on the final descriptor, it will be unable to send any further DMA-
 complete IRQs until it's given more `empty` descriptors. Currently, the driver simply *hopes* that the
 next stmmac_rx_refill() succeeds, risking an indefinite stall of the receive process if not. But this is
 not a regression, so it can be addressed in a future change. (CVE-2026-46110)

Solution

Update the linux library and its related packages to version 6.1.176-1 or later.

See Also

https://advisory.echohq.com/cve/CVE-2026-46110

Plugin Details

Severity: High

ID: 464781

Version: Revision 1.1

Type: Local

Published: 10/2/2026

Updated: 10/2/2026

Risk Information

VPR

Risk Factor: Medium

Score: 5.7

Percentile: 96.44

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

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

CVSS Score Source: CVE-2026-46110

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/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

Patch Publication Date: 5/28/2026

Vulnerability Publication Date: 5/28/2026

Reference Information

CVE: CVE-2026-46110