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Echo: linux: security update to 6.1.176-1

high Tenable Cloud Security Plugin ID 463326

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: qrtr: fix refcount saturation and
 potential UAF in qrtr_port_remove In qrtr_port_remove(), the socket reference count is decremented via
 __sock_put() before the port is removed from the qrtr_ports XArray and before the RCU grace period
 elapses. This breaks the fundamental RCU update paradigm. It exposes a race window where a concurrent RCU
 reader (such as qrtr_reset_ports() or qrtr_port_lookup()) can obtain a pointer to the socket from the
 XArray, and attempt to call sock_hold() on a socket whose reference count has already dropped to zero.
 This exact race condition was hit during syzkaller fuzzing, leading to the following refcount saturation
 warning and a potential Use-After-Free: refcount_t: saturated; leaking memory. WARNING: CPU: 3 PID: 1273
 at lib/refcount.c:22 refcount_warn_saturate+0xae/0x1d0 Modules linked in: qrtr(+) bochs drm_shmem_helper
 ... Call Trace: <TASK> qrtr_reset_ports net/qrtr/af_qrtr.c:768 [inline] [qrtr]
 __qrtr_bind.isra.0+0x48b/0x570 net/qrtr/af_qrtr.c:805 [qrtr] qrtr_bind+0x17d/0x210 net/qrtr/af_qrtr.c:901
 [qrtr] kernel_bind+0xe4/0x120 net/socket.c:3592 qrtr_ns_init+0x1a6/0x380 net/qrtr/ns.c:715 [qrtr]
 qrtr_proto_init+0x3b/0xff0 net/qrtr/af_qrtr.c:169 [qrtr] do_one_initcall+0xf5/0x5e0 init/main.c:1283 ...
 </TASK> Fix this by deferring the reference count decrement until after the xa_erase() and the
 synchronize_rcu() complete. (Note: The v1 of this patch incorrectly replaced __sock_put() with sock_put().
 As Simon Horman pointed out, the callers of qrtr_port_remove() still hold a reference to the socket, so
 freeing the socket memory here would lead to a subsequent UAF in the caller. Thus, the __sock_put() is
 kept, but only repositioned to close the RCU race.) (CVE-2026-52947)

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-2026-52947

Plugin Details

Severity: High

ID: 463326

Version: Revision 1.1

Type: Local

Published: 10/2/2026

Updated: 10/2/2026

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.17

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

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

CVSS Score Source: CVE-2026-52947

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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: 6/25/2026

Vulnerability Publication Date: 6/24/2026

Reference Information

CVE: CVE-2026-52947