Google: sys-kernel/csql-kernel-6_1, sys-kernel/lakitu-kernel-5_15: security update to 17800.519.1

medium Tenable Cloud Security Plugin ID 454608

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: udp: Fix memory accounting leak. Matt
Dowling reported a weird UDP memory usage issue. Under normal operation, the UDP memory usage reported in
/proc/net/sockstat remains close to zero. However, it occasionally spiked to 524,288 pages and never
dropped. Moreover, the value doubled when the application was terminated. Finally, it caused intermittent
packet drops. We can reproduce the issue with the script below [0]: 1. /proc/net/sockstat reports 0 pages
# cat /proc/net/sockstat | grep UDP: UDP: inuse 1 mem 0 2. Run the script till the report reaches 524,288
# python3 test.py & sleep 5 # cat /proc/net/sockstat | grep UDP: UDP: inuse 3 mem 524288 <-- (INT_MAX + 1)
>> PAGE_SHIFT 3. Kill the socket and confirm the number never drops # pkill python3 && sleep 5 # cat
/proc/net/sockstat | grep UDP: UDP: inuse 1 mem 524288 4. (necessary since v6.0) Trigger
proto_memory_pcpu_drain() # python3 test.py & sleep 1 && pkill python3 5. The number doubles # cat
/proc/net/sockstat | grep UDP: UDP: inuse 1 mem 1048577 The application set INT_MAX to SO_RCVBUF, which
triggered an integer overflow in udp_rmem_release(). When a socket is close()d, udp_destruct_common()
purges its receive queue and sums up skb->truesize in the queue. This total is calculated and stored in a
local unsigned integer variable. The total size is then passed to udp_rmem_release() to adjust memory
accounting. However, because the function takes a signed integer argument, the total size can wrap around,
causing an overflow. Then, the released amount is calculated as follows: 1) Add size to
sk->sk_forward_alloc. 2) Round down sk->sk_forward_alloc to the nearest lower multiple of PAGE_SIZE and
assign it to amount. 3) Subtract amount from sk->sk_forward_alloc. 4) Pass amount >> PAGE_SHIFT to
__sk_mem_reduce_allocated(). When the issue occurred, the total in udp_destruct_common() was 2147484480
(INT_MAX + 833), which was cast to -2147482816 in udp_rmem_release(). At 1) sk->sk_forward_alloc is
changed from 3264 to -2147479552, and 2) sets -2147479552 to amount. 3) reverts the wraparound, so we
don't see a warning in inet_sock_destruct(). However, udp_memory_allocated ends up doubling at 4). Since
commit 3cd3399dd7a8 ("net: implement per-cpu reserves for memory_allocated"), memory usage no longer
doubles immediately after a socket is close()d because __sk_mem_reduce_allocated() caches the amount in
udp_memory_per_cpu_fw_alloc. However, the next time a UDP socket receives a packet, the subtraction takes
effect, causing UDP memory usage to double. This issue makes further memory allocation fail once the
socket's sk->sk_rmem_alloc exceeds net.ipv4.udp_rmem_min, resulting in packet drops. To prevent this
issue, let's use unsigned int for the calculation and call sk_forward_alloc_add() only once for the small
delta. Note that first_packet_length() also potentially has the same problem. [0]: from socket import *
SO_RCVBUFFORCE = 33 INT_MAX = (2 ** 31) - 1 s = socket(AF_INET, SOCK_DGRAM) s.bind(('', 0))
s.setsockopt(SOL_SOCKET, SO_RCVBUFFORCE, INT_MAX) c = socket(AF_INET, SOCK_DGRAM)
c.connect(s.getsockname()) data = b'a' * 100 while True: c.send(data) (CVE-2025-22058)

Solution

Update the sys-kernel/csql-kernel-6_1 library and its related packages to version 17800.519.1 or later.

Plugin Details

Severity: Medium

ID: 454608

Version: Revision 1.1

Type: Local

Family: Google COS Security Checks

Published: 10/1/2026

Updated: 10/1/2026

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.19

Vendor

Vendor Severity: LOW

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-2025-22058

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: 4/16/2025

Reference Information

CVE: CVE-2025-22058

Detections

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