CVE-2024-53235

In the Linux kernel, the following vulnerability has been resolved:

erofs: fix file-backed mounts over FUSE

syzbot reported a null-ptr-deref in fusereadargsfill: fusereadfolio+0xb0/0x100 fs/fuse/file.c:905 filemapreadfolio+0xc6/0x2a0 mm/filemap.c:2367 doreadcachefolio+0x263/0x5c0 mm/filemap.c:3825 readmappingfolio include/linux/pagemap.h:1011 [inline] erofsbread+0x34d/0x7e0 fs/erofs/data.c:41 erofsreadsuperblock fs/erofs/super.c:281 [inline] erofsfcfillsuper+0x2b9/0x2500 fs/erofs/super.c:625

Unlike most filesystems, some network filesystems and FUSE need unavoidable valid file pointers for their read I/Os [1]. Anyway, those use cases need to be supported too.

[1] https://docs.kernel.org/filesystems/vfs.html