Description
In the Linux kernel, the following vulnerability has been resolved:
erofs: Fix pcluster memleak when its block address is zero
syzkaller reported a memleak: https://syzkaller.appspot.com/bug?id=62f37ff612f0021641eda5b17f056f1668aa9aed
unreferenced object 0xffff88811009c7f8 (size 136): ... backtrace: [<ffffffff821db19b>] z_erofs_do_read_page+0x99b/0x1740 [<ffffffff821dee9e>] z_erofs_readahead+0x24e/0x580 [<ffffffff814bc0d6>] read_pages+0x86/0x3d0 ...
syzkaller constructed a case: in z_erofs_register_pcluster(), ztailpacking = false and map->m_pa = zero. This makes pcl->obj.index be zero although pcl is not a inline pcluster.
Then following path adds refcount for grp, but the refcount won't be put because pcl is inline.
z_erofs_readahead() z_erofs_do_read_page() # for another page z_erofs_collector_begin() erofs_find_workgroup() erofs_workgroup_get()
Since it's illegal for the block address of a non-inlined pcluster to be zero, add check here to avoid registering the pcluster which would be leaked.
Metrics
No CVSS score has been published yet.
Affected software
No affected versions have been published.
Timeline
- Published
- Dec 24, 2025
- Last modified
- Jun 17, 2026
- NVD status
- Deferred