CVE

CVE-2023-52779

Date: (C)2024-05-22   (M)2024-06-07

In the Linux kernel, the following vulnerability has been resolved: fs: Pass AT_GETATTR_NOSEC flag to getattr interface function When vfs_getattr_nosec() calls a filesystem's getattr interface function then the 'nosec' should propagate into this function so that vfs_getattr_nosec() can again be called from the filesystem's gettattr rather than vfs_getattr(). The latter would add unnecessary security checks that the initial vfs_getattr_nosec() call wanted to avoid. Therefore, introduce the getattr flag GETATTR_NOSEC and allow to pass with the new getattr_flags parameter to the getattr interface function. In overlayfs and ecryptfs use this flag to determine which one of the two functions to call. In a recent code change introduced to IMA vfs_getattr_nosec() ended up calling vfs_getattr() in overlayfs, which in turn called security_inode_getattr() on an exiting process that did not have current->fs set anymore, which then caused a kernel NULL pointer dereference. With this change the call to security_inode_getattr() can be avoided, thus avoiding the NULL pointer dereference.

CVSS Score and Metrics +CVSS Score and Metrics -

CVSS V3 Severity:		CVSS V2 Severity:
CVSS Score : 6.2		CVSS Score :
Exploit Score:		Exploit Score:
Impact Score:		Impact Score:
CVSS V3 Metrics:		CVSS V2 Metrics:
Attack Vector:		Access Vector:
Attack Complexity:		Access Complexity:
Privileges Required:		Authentication:
User Interaction:		Confidentiality:
Scope:		Integrity:
Confidentiality:		Availability:
Integrity:
Availability:

Reference:

https://git.kernel.org/stable/c/3fb0fa08641903304b9d81d52a379ff031dc41d4

https://git.kernel.org/stable/c/8a924db2d7b5eb69ba08b1a0af46e9f1359a9bdf