On Tue, Aug 16, 2022 at 12:08:58PM +0800, Dongliang Mu wrote:
From: Dongliang Mu mudongliangabcd@gmail.com
In alloc_inode, inode_init_always() could return -ENOMEM if security_inode_alloc() fails, which causes inode->i_private uninitialized. Then nilfs_is_metadata_file_inode() returns true and nilfs_free_inode() wrongly calls nilfs_mdt_destroy(), which frees the uninitialized inode->i_private and leads to crashes(e.g., UAF/GPF).
Fix this by moving security_inode_alloc just prior to this_cpu_inc(nr_inodes)
Link: https://lkml.kernel.org/r/CAFcO6XOcf1Jj2SeGt=jJV59wmhESeSKpfR0omdFRq+J9nD1vf... Reported-by: butt3rflyh4ck butterflyhuangxx@gmail.com Reported-by: Hao Sun sunhao.th@gmail.com Reported-by: Jiacheng Xu stitch@zju.edu.cn Signed-off-by: Dongliang Mu mudongliangabcd@gmail.com Cc: Al Viro viro@zeniv.linux.org.uk Cc: stable@vger.kernel.org
Looks good to me, Reviewed-by: Christian Brauner (Microsoft) brauner@kernel.org