Linux Kernel up to 6.5.4 mm/slab_common.c autofs_wait memory leak

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4.6$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.5.4. It has been classified as critical. The affected element is the function autofs_wait of the file mm/slab_common.c. Performing a manipulation results in memory leak. This vulnerability is identified as CVE-2023-54134. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.5.4. It has been classified as critical. This affects the function autofs_wait of the file mm/slab_common.c. The manipulation with an unknown input leads to a memory leak vulnerability. CWE is classifying the issue as CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: autofs: fix memory leak of waitqueues in autofs_catatonic_mode Syzkaller reports a memory leak: BUG: memory leak unreferenced object 0xffff88810b279e00 (size 96): comm "syz-executor399", pid 3631, jiffies 4294964921 (age 23.870s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 08 9e 27 0b 81 88 ff ff ..........'..... 08 9e 27 0b 81 88 ff ff 00 00 00 00 00 00 00 00 ..'............. backtrace: [<ffffffff814cfc90>] kmalloc_trace+0x20/0x90 mm/slab_common.c:1046 [<ffffffff81bb75ca>] kmalloc include/linux/slab.h:576 [inline] [<ffffffff81bb75ca>] autofs_wait+0x3fa/0x9a0 fs/autofs/waitq.c:378 [<ffffffff81bb88a7>] autofs_do_expire_multi+0xa7/0x3e0 fs/autofs/expire.c:593 [<ffffffff81bb8c33>] autofs_expire_multi+0x53/0x80 fs/autofs/expire.c:619 [<ffffffff81bb6972>] autofs_root_ioctl_unlocked+0x322/0x3b0 fs/autofs/root.c:897 [<ffffffff81bb6a95>] autofs_root_ioctl+0x25/0x30 fs/autofs/root.c:910 [<ffffffff81602a9c>] vfs_ioctl fs/ioctl.c:51 [inline] [<ffffffff81602a9c>] __do_sys_ioctl fs/ioctl.c:870 [inline] [<ffffffff81602a9c>] __se_sys_ioctl fs/ioctl.c:856 [inline] [<ffffffff81602a9c>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:856 [<ffffffff84608225>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff84608225>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [<ffffffff84800087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd autofs_wait_queue structs should be freed if their wait_ctr becomes zero. Otherwise they will be lost. In this case an AUTOFS_IOC_EXPIRE_MULTI ioctl is done, then a new waitqueue struct is allocated in autofs_wait(), its initial wait_ctr equals 2. After that wait_event_killable() is interrupted (it returns -ERESTARTSYS), so that 'wq->name.name == NULL' condition may be not satisfied. Actually, this condition can be satisfied when autofs_wait_release() or autofs_catatonic_mode() is called and, what is also important, wait_ctr is decremented in those places. Upon the exit of autofs_wait(), wait_ctr is decremented to 1. Then the unmounting process begins: kill_sb calls autofs_catatonic_mode(), which should have freed the waitqueues, but it only decrements its usage counter to zero which is not a correct behaviour. edit:imk This description is of course not correct. The umount performed as a result of an expire is a umount of a mount that has been automounted, it's not the autofs mount itself. They happen independently, usually after everything mounted within the autofs file system has been expired away. If everything hasn't been expired away the automount daemon can still exit leaving mounts in place. But expires done in both cases will result in a notification that calls autofs_wait_release() with a result status. The problem case is the summary execution of of the automount daemon. In this case any waiting processes won't be woken up until either they are terminated or the mount is umounted. end edit: imk So in catatonic mode we should free waitqueues which counter becomes zero. edit: imk Initially I was concerned that the calling of autofs_wait_release() and autofs_catatonic_mode() was not mutually exclusive but that can't be the case (obviously) because the queue entry (or entries) is removed from the list when either of these two functions are called. Consequently the wait entry will be freed by only one of these functions or by the woken process in autofs_wait() depending on the order of the calls. end edit: imk

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2023-54134 since 12/24/2025. The exploitability is told to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 279774 (Linux Distros Unpatched Vulnerability : CVE-2023-54134), 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 1985e8eae8627f02e3364690c5fed7af1c46be55/976abbdc120a97049b9133e60fa7b29627d11de4/6079dc77c6f32936e8a6766ee8334ae3c99f4504/69ddafc7a7afd8401bab53eff5af813fa0d368a2/71eeddcad7342292c19042c290c477697acaccab/726deae613bc1b6096ad3b61cc1e63e33330fbc2/696b625f3f85d80fca48c24d2948fbc451e74366/ccbe77f7e45dfb4420f7f531b650c00c6e9c7507 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 (279774) and CERT Bund (WID-SEC-2025-2929). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

  • Open Source Linux Kernel

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
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CVSSv3info

VulDB Meta Base Score: 4.8
VulDB Meta Temp Score: 4.6

VulDB Base Score: 4.8
VulDB Temp Score: 4.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔒
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VulDB Reliability: 🔍

Exploitinginfo

Class: Memory leak
CWE: CWE-401 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

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EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 279774
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2023-54134

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: 1985e8eae8627f02e3364690c5fed7af1c46be55/976abbdc120a97049b9133e60fa7b29627d11de4/6079dc77c6f32936e8a6766ee8334ae3c99f4504/69ddafc7a7afd8401bab53eff5af813fa0d368a2/71eeddcad7342292c19042c290c477697acaccab/726deae613bc1b6096ad3b61cc1e63e33330fbc2/696b625f3f85d80fca48c24d2948fbc451e74366/ccbe77f7e45dfb4420f7f531b650c00c6e9c7507

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-2023-54134 (🔒)
GCVE (CVE): GCVE-0-2023-54134
GCVE (VulDB): GCVE-100-338091
CERT Bund: WID-SEC-2025-2929 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 12/24/2025 15:07
Updated: 01/03/2026 05:37
Changes: 12/24/2025 15:07 (59), 12/25/2025 18:04 (1), 12/29/2025 00:21 (2), 01/03/2026 05:37 (7)
Complete: 🔍
Cache ID: 216::103

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