PT-2026-51912 · Linux · Linux

Published

2026-06-24

·

Updated

2026-06-24

·

CVE-2026-53018

None

No severity ratings or metrics are available. When they are, we'll update the corresponding info on the page.
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.
Found an issue in the description? Have something to add? Feel free to write us 👾
dbugs@ptsecurity.com

Related Identifiers

CVE-2026-53018

Affected Products

Linux