Linux Kernel up to 6.5.4 dbUnmount double free

CVSS Meta Temp Score
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CTI Interest Score
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6.8$0-$5k0.00

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.5.4 and classified as critical. Impacted is the function dbUnmount. Performing a manipulation results in double free. This vulnerability is known as CVE-2023-54127. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.5.4. It has been classified as critical. This affects the function dbUnmount. The manipulation with an unknown input leads to a double free vulnerability. CWE is classifying the issue as CWE-415. The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: fs/jfs: prevent double-free in dbUnmount() after failed jfs_remount() Syzkaller reported the following issue: ================================================================== BUG: KASAN: double-free in slab_free mm/slub.c:3787 [inline] BUG: KASAN: double-free in __kmem_cache_free+0x71/0x110 mm/slub.c:3800 Free of addr ffff888086408000 by task syz-executor.4/12750 [...] Call Trace: <TASK> [...] kasan_report_invalid_free+0xac/0xd0 mm/kasan/report.c:482 ____kasan_slab_free+0xfb/0x120 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1807 slab_free mm/slub.c:3787 [inline] __kmem_cache_free+0x71/0x110 mm/slub.c:3800 dbUnmount+0xf4/0x110 fs/jfs/jfs_dmap.c:264 jfs_umount+0x248/0x3b0 fs/jfs/jfs_umount.c:87 jfs_put_super+0x86/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x130/0x310 fs/super.c:492 kill_block_super+0x79/0xd0 fs/super.c:1386 deactivate_locked_super+0xa7/0xf0 fs/super.c:332 cleanup_mnt+0x494/0x520 fs/namespace.c:1291 task_work_run+0x243/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x124/0x150 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb2/0x140 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:296 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd [...] </TASK> Allocated by task 13352: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x3d/0x60 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:371 [inline] __kasan_kmalloc+0x97/0xb0 mm/kasan/common.c:380 kmalloc include/linux/slab.h:580 [inline] dbMount+0x54/0x980 fs/jfs/jfs_dmap.c:164 jfs_mount+0x1dd/0x830 fs/jfs/jfs_mount.c:121 jfs_fill_super+0x590/0xc50 fs/jfs/super.c:556 mount_bdev+0x26c/0x3a0 fs/super.c:1359 legacy_get_tree+0xea/0x180 fs/fs_context.c:610 vfs_get_tree+0x88/0x270 fs/super.c:1489 do_new_mount+0x289/0xad0 fs/namespace.c:3145 do_mount fs/namespace.c:3488 [inline] __do_sys_mount fs/namespace.c:3697 [inline] __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3674 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 13352: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x3d/0x60 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:518 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1807 slab_free mm/slub.c:3787 [inline] __kmem_cache_free+0x71/0x110 mm/slub.c:3800 dbUnmount+0xf4/0x110 fs/jfs/jfs_dmap.c:264 jfs_mount_rw+0x545/0x740 fs/jfs/jfs_mount.c:247 jfs_remount+0x3db/0x710 fs/jfs/super.c:454 reconfigure_super+0x3bc/0x7b0 fs/super.c:935 vfs_fsconfig_locked fs/fsopen.c:254 [inline] __do_sys_fsconfig fs/fsopen.c:439 [inline] __se_sys_fsconfig+0xad5/0x1060 fs/fsopen.c:314 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd [...] JFS_SBI(ipbmap->i_sb)->bmap wasn't set to NULL after kfree() in dbUnmount(). Syzkaller uses faultinject to reproduce this KASAN double-free warning. The issue is triggered if either diMount() or dbMount() fail in jfs_remount(), since diUnmount() or dbUnmount() already happened in such a case - they will do double-free on next execution: jfs_umount or jfs_remount. Tested on both upstream and jfs-next by syzkaller.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2023-54127 since 12/24/2025. The exploitability is told to be difficult. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 01/03/2026).

The vulnerability scanner Nessus provides a plugin with the ID 280047 (Linux Distros Unpatched Vulnerability : CVE-2023-54127), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.14.326, 4.19.295, 5.4.257, 5.10.197, 5.15.133, 6.1.55 or 6.5.5 eliminates this vulnerability. Applying the patch 798c5f6f98bc9045593d4b3a65c32f05d97bd0e6/aef6507e85475e30831c30405d785c7ed976ea4a/b12ccbfdf6539ef0157868f69fcae0b7f7a072b3/6f8b34458948ffca2fe90cd8c614e3fa2ebe0b27/aa5b019a3e0f7f54f4e5370c1af827f6b00fd26b/2f7a36448f51d08d3a83f1514abcca4b680bcd3c/f71c4bb3ec08dfcbd201350a6a0a914c4e6a9e3f/cade5397e5461295f3cb87880534b6a07cafa427 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (280047) and CERT Bund (WID-SEC-2025-2929). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

  • Open Source Linux Kernel

Productinfo

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Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.1
VulDB Meta Temp Score: 6.8

VulDB Base Score: 7.1
VulDB Temp Score: 6.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Double free
CWE: CWE-415 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 280047
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2023-54127

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 4.14.326/4.19.295/5.4.257/5.10.197/5.15.133/6.1.55/6.5.5
Patch: 798c5f6f98bc9045593d4b3a65c32f05d97bd0e6/aef6507e85475e30831c30405d785c7ed976ea4a/b12ccbfdf6539ef0157868f69fcae0b7f7a072b3/6f8b34458948ffca2fe90cd8c614e3fa2ebe0b27/aa5b019a3e0f7f54f4e5370c1af827f6b00fd26b/2f7a36448f51d08d3a83f1514abcca4b680bcd3c/f71c4bb3ec08dfcbd201350a6a0a914c4e6a9e3f/cade5397e5461295f3cb87880534b6a07cafa427

Timelineinfo

12/24/2025 Advisory disclosed
12/24/2025 +0 days CVE reserved
12/24/2025 +0 days VulDB entry created
01/03/2026 +10 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2023-54127 (🔒)
GCVE (CVE): GCVE-0-2023-54127
GCVE (VulDB): GCVE-100-338145
CERT Bund: WID-SEC-2025-2929 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 12/24/2025 15:15
Updated: 01/03/2026 04:20
Changes: 12/24/2025 15:15 (58), 12/25/2025 18:04 (1), 12/27/2025 03:59 (2), 01/03/2026 04:20 (7)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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