CVE-2025-38221 | ext4: fix out of bounds punch offset

In the Linux kernel, the following vulnerability has been resolved: ext4: fix out of bounds punch offset Punching a hole with a start offset that exceeds max_end is not permitted and will result in a negative length in the truncate_inode_partial_folio() function while truncating the page cache, potentially leading to undesirable consequences. A simple reproducer: truncate -s 9895604649994 /mnt/foo xfs_io -c "pwrite 8796093022208 4096" /mnt/foo xfs_io -c "fpunch 8796093022213 25769803777" /mnt/foo kernel BUG at include/linux/highmem.h:275! Oops: invalid opcode: 0000 [#1] SMP PTI CPU: 3 UID: 0 PID: 710 Comm: xfs_io Not tainted 6.15.0-rc3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:zero_user_segments.constprop.0+0xd7/0x110 RSP: 0018:ffffc90001cf3b38 EFLAGS: 00010287 RAX: 0000000000000005 RBX: ffffea0001485e40 RCX: 0000000000001000 RDX: 000000000040b000 RSI: 0000000000000005 RDI: 000000000040b000 RBP: 000000000040affb R08: ffff888000000000 R09: ffffea0000000000 R10: 0000000000000003 R11: 00000000fffc7fc5 R12: 0000000000000005 R13: 000000000040affb R14: ffffea0001485e40 R15: ffff888031cd3000 FS: 00007f4f63d0b780(0000) GS:ffff8880d337d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000001ae0b038 CR3: 00000000536aa000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> truncate_inode_partial_folio+0x3dd/0x620 truncate_inode_pages_range+0x226/0x720 ? bdev_getblk+0x52/0x3e0 ? ext4_get_group_desc+0x78/0x150 ? crc32c_arch+0xfd/0x180 ? __ext4_get_inode_loc+0x18c/0x840 ? ext4_inode_csum+0x117/0x160 ? jbd2_journal_dirty_metadata+0x61/0x390 ? __ext4_handle_dirty_metadata+0xa0/0x2b0 ? kmem_cache_free+0x90/0x5a0 ? jbd2_journal_stop+0x1d5/0x550 ? __ext4_journal_stop+0x49/0x100 truncate_pagecache_range+0x50/0x80 ext4_truncate_page_cache_block_range+0x57/0x3a0 ext4_punch_hole+0x1fe/0x670 ext4_fallocate+0x792/0x17d0 ? __count_memcg_events+0x175/0x2a0 vfs_fallocate+0x121/0x560 ksys_fallocate+0x51/0xc0 __x64_sys_fallocate+0x24/0x40 x64_sys_call+0x18d2/0x4170 do_syscall_64+0xa7/0x220 entry_SYSCALL_64_after_hwframe+0x76/0x7e Fix this by filtering out cases where the punching start offset exceeds max_end.

Published: 2025-07-04 Last update: 2025-11-18 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Conclusion & alert: CVE-2025-38221 is rated Low Risk (34/100): CVSS High severity, with low exploitation likelihood (EPSS 0.05%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-38221

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-30 0.02% 0.05% +0.03%
2 2025-07-05 0.02%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-38221

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.1 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 5.2 [email protected]

Weakness enumeration for CVE-2025-38221

OS Trackers for CVE-2025-38221

vendor priority summary link
debian unimportant CVE-2025-38221 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2025-38221
redhat https://access.redhat.com/security/cve/CVE-2025-38221
suse medium CVE-2025-38221 severity moderate: SUSE including 26 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 281 product×package rows across 55 product lines (SLES-LTSS-TERADATA 15 SP2, SUSE Linux Enterprise High Availability Extension 15 SP7, … (55 product lines)): Known Not Affected 281. https://www.suse.com/security/cve/CVE-2025-38221/
ubuntu medium CVE-2025-38221 medium priority: Ubuntu including 144 source packages (linux, linux-allwinner-5.19, …), 1289 status rows across 9 suites (bionic, focal, jammy, noble, oracular, plucky, trusty, upstream, xenial): DNE 925, ignored 151, not-affected 136, released 77. https://ubuntu.com/security/CVE-2025-38221

Affected software / configurations for CVE-2025-38221

Vendor Product Version Raw CPE
linux linux_kernel >= 6.15, < 6.15.4 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

References for CVE-2025-38221

cvelogic Threat Intelligence