CVE-2023-53260

/// Technical description

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

ovl: fix null pointer dereference in ovl_permission()

Following process:

P1 P2

path_lookupat

link_path_walk

inode_permission

ovl_permission

ovl_i_path_real(inode, &realpath)

path->dentry = ovl_i_dentry_upper(inode)

drop_cache

__dentry_kill(ovl_dentry)

iput(ovl_inode)

ovl_destroy_inode(ovl_inode)

dput(oi->__upperdentry)

dentry_kill(upperdentry)

dentry_unlink_inode

upperdentry->d_inode = NULL

realinode = d_inode(realpath.dentry) // return NULL

inode_permission(realinode)

inode->i_sb // NULL pointer dereference

, will trigger an null pointer dereference at realinode:

[ 335.664979] BUG: kernel NULL pointer dereference,

address: 0000000000000002

[ 335.668032] CPU: 0 PID: 2592 Comm: ls Not tainted 6.3.0

[ 335.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References