Bottlerocket: bottlerocket-kernel-6.12, kernel-6.12: security update to 6.12.29

medium Tenable Cloud Security Plugin ID 428257

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: btrfs: do proper folio cleanup when
cow_file_range() failed [BUG] When testing with COW fixup marked as BUG_ON() (this is involved with the
new pin_user_pages*() change, which should not result new out-of-band dirty pages), I hit a crash
triggered by the BUG_ON() from hitting COW fixup path. This BUG_ON() happens just after a failed
btrfs_run_delalloc_range(): BTRFS error (device dm-2): failed to run delalloc range, root 348 ino 405
folio 65536 submit_bitmap 6-15 start 90112 len 106496: -28 ------------[ cut here ]------------ kernel BUG
at fs/btrfs/extent_io.c:1444! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP CPU: 0 UID: 0 PID:
434621 Comm: kworker/u24:8 Tainted: G OE 6.12.0-rc7-custom+ #86 Hardware name: QEMU KVM Virtual Machine,
BIOS unknown 2/2/2022 Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] pc :
extent_writepage_io+0x2d4/0x308 [btrfs] lr : extent_writepage_io+0x2d4/0x308 [btrfs] Call trace:
extent_writepage_io+0x2d4/0x308 [btrfs] extent_writepage+0x218/0x330 [btrfs]
extent_write_cache_pages+0x1d4/0x4b0 [btrfs] btrfs_writepages+0x94/0x150 [btrfs] do_writepages+0x74/0x190
filemap_fdatawrite_wbc+0x88/0xc8 start_delalloc_inodes+0x180/0x3b0 [btrfs]
btrfs_start_delalloc_roots+0x174/0x280 [btrfs] shrink_delalloc+0x114/0x280 [btrfs] flush_space+0x250/0x2f8
[btrfs] btrfs_async_reclaim_data_space+0x180/0x228 [btrfs] process_one_work+0x164/0x408
worker_thread+0x25c/0x388 kthread+0x100/0x118 ret_from_fork+0x10/0x20 Code: aa1403e1 9402f3ef aa1403e0
9402f36f (d4210000) ---[ end trace 0000000000000000 ]--- [CAUSE] That failure is mostly from
cow_file_range(), where we can hit -ENOSPC. Although the -ENOSPC is already a bug related to our space
reservation code, let's just focus on the error handling. For example, we have the following dirty range
[0, 64K) of an inode, with 4K sector size and 4K page size: 0 16K 32K 48K 64K
|///////////////////////////////////////| |#######################################| Where |///| means page
are still dirty, and |###| means the extent io tree has EXTENT_DELALLOC flag. - Enter extent_writepage()
for page 0 - Enter btrfs_run_delalloc_range() for range [0, 64K) - Enter cow_file_range() for range [0,
64K) - Function btrfs_reserve_extent() only reserved one 16K extent So we created extent map and ordered
extent for range [0, 16K) 0 16K 32K 48K 64K |////////|//////////////////////////////| |<- OE
->|##############################| And range [0, 16K) has its delalloc flag cleared. But since we haven't
yet submit any bio, involved 4 pages are still dirty. - Function btrfs_reserve_extent() returns with
-ENOSPC Now we have to run error cleanup, which will clear all EXTENT_DELALLOC* flags and clear the dirty
flags for the remaining ranges: 0 16K 32K 48K 64K |////////| | | | | Note that range [0, 16K) still has
its pages dirty. - Some time later, writeback is triggered again for the range [0, 16K) since the page
range still has dirty flags. - btrfs_run_delalloc_range() will do nothing because there is no
EXTENT_DELALLOC flag. - extent_writepage_io() finds page 0 has no ordered flag Which falls into the COW
fixup path, triggering the BUG_ON(). Unfortunately this error handling bug dates back to the introduction
of btrfs. Thankfully with the abuse of COW fixup, at least it won't crash the kernel. [FIX] Instead of
immediately unlocking the extent and folios, we keep the extent and folios locked until either erroring
out or the whole delalloc range finished. When the whole delalloc range finished without error, we just
unlock the whole range with PAGE_SET_ORDERED (and PAGE_UNLOCK for !keep_locked cases) ---truncated---
(CVE-2024-57976)

Plugin Details

Severity: Medium

ID: 428257

Version: Revision 1.7

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: 23.15

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-2024-57976

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: 2/27/2025

Reference Information

CVE: CVE-2024-57976

Detections

Analytics