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Echo: linux: security update to 6.1.176-1

high Tenable Cloud Security Plugin ID 462796

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: f2fs: fix use-after-free of sbi in
 f2fs_compress_write_end_io() In f2fs_compress_write_end_io(), dec_page_count(sbi, type) can bring the
 F2FS_WB_CP_DATA counter to zero, unblocking f2fs_wait_on_all_pages() in f2fs_put_super() on a concurrent
 unmount CPU. The unmount path then proceeds to call f2fs_destroy_page_array_cache(sbi), which destroys
 sbi->page_array_slab via kmem_cache_destroy(), and eventually kfree(sbi). Meanwhile, the bio completion
 callback is still executing: when it reaches page_array_free(sbi, ...), it dereferences
 sbi->page_array_slab — a destroyed slab cache — to call kmem_cache_free(), causing a use-after-free. This
 is the same class of bug as CVE-2026-23234 (which fixed the equivalent race in f2fs_write_end_io() in
 data.c), but in the compressed writeback completion path that was not covered by that fix. Fix this by
 moving dec_page_count() to after page_array_free(), so that all sbi accesses complete before the counter
 decrement that can unblock unmount. For non-last folios (where atomic_dec_return on cic->pending_pages is
 nonzero), dec_page_count is called immediately before returning — page_array_free is not reached on this
 path, so there is no post-decrement sbi access. For the last folio, page_array_free runs while the
 F2FS_WB_CP_DATA counter is still nonzero (this folio has not yet decremented it), keeping sbi alive, and
 dec_page_count runs as the final operation. (CVE-2026-31702)

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-2026-31702

Plugin Details

Severity: High

ID: 462796

Version: Revision 1.1

Type: Local

Published: 10/2/2026

Updated: 10/2/2026

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 57.83

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-2026-31702

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: 5/2/2026

Vulnerability Publication Date: 5/1/2026

Reference Information

CVE: CVE-2026-31702