CVE-2022-50743

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

References

• https://git.kernel.org/stable/c/ac54c1f7b288d83b6ba1e320efff24ecc21309cd ↗
• https://git.kernel.org/stable/c/618e712b99c78d1004b70a1a9ab0a4830d0b2673 ↗
• https://git.kernel.org/stable/c/c42c0ffe81176940bd5dead474216b7198d77675 ↗