CVE-2023-54153
Unknown Unknown - Not Provided
Use-After-Free in Linux Kernel ext4 Quota Handling on Mount Failure

Publication date: 2025-12-24

Last updated on: 2025-12-24

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: ext4: turn quotas off if mount failed after enabling quotas Yi found during a review of the patch "ext4: don't BUG on inconsistent journal feature" that when ext4_mark_recovery_complete() returns an error value, the error handling path does not turn off the enabled quotas, which triggers the following kmemleak: ================================================================ unreferenced object 0xffff8cf68678e7c0 (size 64): comm "mount", pid 746, jiffies 4294871231 (age 11.540s) hex dump (first 32 bytes): 00 90 ef 82 f6 8c ff ff 00 00 00 00 41 01 00 00 ............A... c7 00 00 00 bd 00 00 00 0a 00 00 00 48 00 00 00 ............H... backtrace: [<00000000c561ef24>] __kmem_cache_alloc_node+0x4d4/0x880 [<00000000d4e621d7>] kmalloc_trace+0x39/0x140 [<00000000837eee74>] v2_read_file_info+0x18a/0x3a0 [<0000000088f6c877>] dquot_load_quota_sb+0x2ed/0x770 [<00000000340a4782>] dquot_load_quota_inode+0xc6/0x1c0 [<0000000089a18bd5>] ext4_enable_quotas+0x17e/0x3a0 [ext4] [<000000003a0268fa>] __ext4_fill_super+0x3448/0x3910 [ext4] [<00000000b0f2a8a8>] ext4_fill_super+0x13d/0x340 [ext4] [<000000004a9489c4>] get_tree_bdev+0x1dc/0x370 [<000000006e723bf1>] ext4_get_tree+0x1d/0x30 [ext4] [<00000000c7cb663d>] vfs_get_tree+0x31/0x160 [<00000000320e1bed>] do_new_mount+0x1d5/0x480 [<00000000c074654c>] path_mount+0x22e/0xbe0 [<0000000003e97a8e>] do_mount+0x95/0xc0 [<000000002f3d3736>] __x64_sys_mount+0xc4/0x160 [<0000000027d2140c>] do_syscall_64+0x3f/0x90 ================================================================ To solve this problem, we add a "failed_mount10" tag, and call ext4_quota_off_umount() in this tag to release the enabled qoutas.
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Meta Information
Published
2025-12-24
Last Modified
2025-12-24
Generated
2026-05-07
AI Q&A
2025-12-25
EPSS Evaluated
2026-05-05
NVD
EUVD
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
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AI Powered Q&A
What immediate steps should I take to mitigate this vulnerability?

The vulnerability is resolved by ensuring that quotas are turned off if the ext4 mount fails after enabling quotas. Immediate mitigation involves applying the patch that adds a 'failed_mount10' tag and calls ext4_quota_off_umount() to release enabled quotas when mount fails. Therefore, update your Linux kernel to a version that includes this fix.


Can you explain this vulnerability to me?

This vulnerability occurs in the Linux kernel's ext4 filesystem code. When enabling quotas during a mount operation, if the function ext4_mark_recovery_complete() returns an error, the error handling does not properly disable the enabled quotas. This leads to a memory leak (kmemleak) because the quotas remain enabled even though the mount failed. The fix involves adding a mechanism to turn off quotas if the mount fails after enabling them.


How can this vulnerability impact me? :

This vulnerability can cause a memory leak in the Linux kernel when mounting ext4 filesystems with quotas enabled. Over time, this could lead to increased memory usage and potentially degrade system performance or stability due to unreleased quota resources.


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