CVE-2026-53018

What it is

In the Linux kernel, the following vulnerability has been resolved: f2fs: avoid reading already updated pages during GC We found the following issue during fuzz testing: page: refcount:3 mapcount:0 mapping:00000000b6e89c65 index:0x18b2dc pfn:0x161ba9 memcg:f8ffff800e269c00 aops:f2fs_meta_aops ino:2 flags: 0x52880000000080a9(locked|waiters|uptodate|lru|private|zone=1|kasantag=0x4a) raw: 52880000000080a9 fffffffec6e17588 fffffffec0ccc088 a7ffff8067063618 raw: 000000000018b2dc 0000000000000009 00000003ffffffff f8ffff800e269c00 page dumped because: VM_BUG_ON_FOLIO(folio_test_uptodate(folio)) page_owner tracks the page as allocated post_alloc_hook+0x58c/0x5ec prep_new_page+0x34/0x284 get_page_from_freelist+0x2dcc/0x2e8c __alloc_pages_noprof+0x280/0x76c __folio_alloc_noprof+0x18/0xac __filemap_get_folio+0x6bc/0xdc4 pagecache_get_page+0x3c/0x104 do_garbage_collect+0x5c78/0x77a4 f2fs_gc+0xd74/0x25f0 gc_thread_func+0xb28/0x2930 kthread+0x464/0x5d8 ret_from_fork+0x10/0x20 ------------[ cut here ]------------ kernel BUG at mm/filemap.c:1563! folio_end_read+0x140/0x168 f2fs_finish_read_bio+0x5c4/0xb80 f2fs_read_end_io+0x64c/0x708 bio_endio+0x85c/0x8c0 blk_update_request+0x690/0x127c scsi_end_request+0x9c/0xb8c scsi_io_completion+0xf0/0x250 scsi_finish_command+0x430/0x45c scsi_complete+0x178/0x6d4 blk_mq_complete_request+0xcc/0x104 scsi_done_internal+0x214/0x454 scsi_done+0x24/0x34 which is similar to the problem reported by syzbot: https://syzkaller.appspot.com/bug?extid=3686758660f980b402dc This case is consistent with the description in commit 9bf1a3f ("f2fs: avoid GC causing encrypted file corrupted"): Page 1 is moved from blkaddr A to blkaddr B by move_data_block, and after being written it is marked as uptodate. Then, Page 1 is moved from blkaddr B to blkaddr C, VM_BUG_ON_FOLIO was triggered in the endio initiated by ra_data_block. There is no need to read Page 1 again from blkaddr B, since it has already been updated. Therefore, avoid initiating I/O in this case.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of 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. 2026-06-24 17:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-30 13:19 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: 5.5 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-06-24 17:17 UTC

Last modified

2026-10-30 13:19 UTC

Exploit probability

0.2% · EPSS, next 30 days

Record status

Modified

Affected

• Linux Kernel < 6.18.33
• Linux Kernel < 7.0.10

Attack profile CVSS 3.1 · 5.5

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

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-2026-53018.md and follow it. Check whether this project is affected by CVE-2026-53018. 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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