CVE-2023-53100

What it is

In the Linux kernel, the following vulnerability has been resolved: ext4: fix WARNING in ext4_update_inline_data Syzbot found the following issue: EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 without journal. Quota mode: none. fscrypt: AES-256-CTS-CBC using implementation "cts-cbc-aes-aesni" fscrypt: AES-256-XTS using implementation "xts-aes-aesni" ------------[ cut here ]------------ WARNING: CPU: 0 PID: 5071 at mm/page_alloc.c:5525 __alloc_pages+0x30a/0x560 mm/page_alloc.c:5525 Modules linked in: CPU: 1 PID: 5071 Comm: syz-executor263 Not tainted 6.2.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:__alloc_pages+0x30a/0x560 mm/page_alloc.c:5525 RSP: 0018:ffffc90003c2f1c0 EFLAGS: 00010246 RAX: ffffc90003c2f220 RBX: 0000000000000014 RCX: 0000000000000000 RDX: 0000000000000028 RSI: 0000000000000000 RDI: ffffc90003c2f248 RBP: ffffc90003c2f2d8 R08: dffffc0000000000 R09: ffffc90003c2f220 R10: fffff52000785e49 R11: 1ffff92000785e44 R12: 0000000000040d40 R13: 1ffff92000785e40 R14: dffffc0000000000 R15: 1ffff92000785e3c FS: 0000555556c0d300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f95d5e04138 CR3: 00000000793aa000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __alloc_pages_node include/linux/gfp.h:237 [inline] alloc_pages_node include/linux/gfp.h:260 [inline] __kmalloc_large_node+0x95/0x1e0 mm/slab_common.c:1113 __do_kmalloc_node mm/slab_common.c:956 [inline] __kmalloc+0xfe/0x190 mm/slab_common.c:981 kmalloc include/linux/slab.h:584 [inline] kzalloc include/linux/slab.h:720 [inline] ext4_update_inline_data+0x236/0x6b0 fs/ext4/inline.c:346 ext4_update_inline_dir fs/ext4/inline.c:1115 [inline] ext4_try_add_inline_entry+0x328/0x990 fs/ext4/inline.c:1307 ext4_add_entry+0x5a4/0xeb0 fs/ext4/namei.c:2385 ext4_add_nondir+0x96/0x260 fs/ext4/namei.c:2772 ext4_create+0x36c/0x560 fs/ext4/namei.c:2817 lookup_open fs/namei.c:3413 [inline] open_last_lookups fs/namei.c:3481 [inline] path_openat+0x12ac/0x2dd0 fs/namei.c:3711 do_filp_open+0x264/0x4f0 fs/namei.c:3741 do_sys_openat2+0x124/0x4e0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1337 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 Above issue happens as follows: ext4_iget ext4_find_inline_data_nolock ->i_inline_off=164 i_inline_size=60 ext4_try_add_inline_entry __ext4_mark_inode_dirty ext4_expand_extra_isize_ea ->i_extra_isize=32 s_want_extra_isize=44 ext4_xattr_shift_entries ->after shift i_inline_off is incorrect, actually is change to 176 ext4_try_add_inline_entry ext4_update_inline_dir get_max_inline_xattr_value_size if (EXT4_I(inode)->i_inline_off) entry = (struct ext4_xattr_entry *)((void *)raw_inode + EXT4_I(inode)->i_inline_off); free += EXT4_XATTR_SIZE(le32_to_cpu(entry->e_value_size)); ->As entry is incorrect, then 'free' may be negative ext4_update_inline_data value = kzalloc(len, GFP_NOFS); -> len is unsigned int, maybe very large, then trigger warning when 'kzalloc()' To resolve the above issue we need to update 'i_inline_off' after 'ext4_xattr_shift_entries()'. We do not need to set EXT4_STATE_MAY_INLINE_DATA flag here, since ext4_mark_inode_dirty() already sets this flag if needed. Setting EXT4_STATE_MAY_INLINE_DATA when it is needed may trigger a BUG_ON in ext4_writepages().

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2025-05-02 16:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-15 22:17 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.2% in the next 30 days (EPSS).
• Severity: 7.8 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2025-05-02 16:15 UTC

Last modified

2026-10-15 22:17 UTC

Exploit probability

0.2% · EPSS, next 30 days

Record status

Modified

Affected

• Linux Kernel < 4.14.310
• Linux Kernel < 4.19.278
• Linux Kernel < 5.4.237
• Linux Kernel < 5.10.175
• Linux Kernel < 5.15.103
• Linux Kernel < 6.1.20
• Linux Kernel < 6.2.7
• Linux Kernel 6.3

Attack profile CVSS 3.1 · 7.8

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2023-53100.md and follow it. Check whether this project is affected by CVE-2023-53100. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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