CVE-2023-54194
Unknown Unknown - Not Provided

Memory Allocation Failure in Linux exFAT Driver Causes Mount Issues

Publication date: 2025-12-30

Last updated on: 2025-12-30

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: exfat: use kvmalloc_array/kvfree instead of kmalloc_array/kfree The call stack shown below is a scenario in the Linux 4.19 kernel. Allocating memory failed where exfat fs use kmalloc_array due to system memory fragmentation, while the u-disk was inserted without recognition. Devices such as u-disk using the exfat file system are pluggable and may be insert into the system at any time. However, long-term running systems cannot guarantee the continuity of physical memory. Therefore, it's necessary to address this issue. Binder:2632_6: page allocation failure: order:4, mode:0x6040c0(GFP_KERNEL|__GFP_COMP), nodemask=(null) Call trace: [242178.097582] dump_backtrace+0x0/0x4 [242178.097589] dump_stack+0xf4/0x134 [242178.097598] warn_alloc+0xd8/0x144 [242178.097603] __alloc_pages_nodemask+0x1364/0x1384 [242178.097608] kmalloc_order+0x2c/0x510 [242178.097612] kmalloc_order_trace+0x40/0x16c [242178.097618] __kmalloc+0x360/0x408 [242178.097624] load_alloc_bitmap+0x160/0x284 [242178.097628] exfat_fill_super+0xa3c/0xe7c [242178.097635] mount_bdev+0x2e8/0x3a0 [242178.097638] exfat_fs_mount+0x40/0x50 [242178.097643] mount_fs+0x138/0x2e8 [242178.097649] vfs_kern_mount+0x90/0x270 [242178.097655] do_mount+0x798/0x173c [242178.097659] ksys_mount+0x114/0x1ac [242178.097665] __arm64_sys_mount+0x24/0x34 [242178.097671] el0_svc_common+0xb8/0x1b8 [242178.097676] el0_svc_handler+0x74/0x90 [242178.097681] el0_svc+0x8/0x340 By analyzing the exfat code,we found that continuous physical memory is not required here,so kvmalloc_array is used can solve this problem.

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Meta Information

Published
2025-12-30
Last Modified
2025-12-30
Generated
2026-07-06
AI Q&A
2025-12-30
EPSS Evaluated
2026-07-05
NVD
CVE-2023-54194

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel 4.19

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Exploitability

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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability occurs in the Linux kernel's exfat file system implementation where memory allocation uses kmalloc_array, which requires continuous physical memory. Due to system memory fragmentation, this allocation can fail when a u-disk formatted with exfat is inserted, causing the device not to be recognized. The fix replaces kmalloc_array/kfree with kvmalloc_array/kvfree, which does not require continuous physical memory, thus preventing allocation failures during mounting of exfat file systems.

Impact Analysis

The impact of this vulnerability is that when a u-disk using the exfat file system is inserted into a Linux system with fragmented memory, the system may fail to allocate memory properly, causing the device not to be recognized or mounted. This can lead to loss of access to the inserted storage device and potential disruption in workflows relying on such devices.

Detection Guidance

This vulnerability can be detected by monitoring kernel logs for memory allocation failures related to exfat filesystem mounting. Specifically, look for messages indicating 'page allocation failure' and call traces involving kmalloc_array failures when inserting exfat-formatted USB devices. You can use the command 'dmesg | grep -i exfat' or 'journalctl -k | grep -i exfat' to check for such errors in kernel logs.

Mitigation Strategies

Immediate mitigation involves updating the Linux kernel to a version where the exfat filesystem uses kvmalloc_array/kvfree instead of kmalloc_array/kfree, as this change addresses memory allocation failures due to system memory fragmentation. Until the update is applied, avoid inserting exfat-formatted USB devices into long-running systems that may have fragmented physical memory.

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