NULL pointer dereference in Linux kernel - CVE-2018-1095
Published: April 4, 2018
Vulnerability identifier: #VU11521
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2018-1095
CWE-ID: CWE-476
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local attacker to cause DoS condition on the target system.
The weakness exists due to improper validation of xattr sizes when using the ext4_xattr_check_entries function, as defined in the fs/ext4/super.c source code file. A local attacker can mount a malicious ext4 image, trigger NULL pointer dereference in the fs/posix_acl.c:get_acl() function and cause the service to crash.
The weakness exists due to improper validation of xattr sizes when using the ext4_xattr_check_entries function, as defined in the fs/ext4/super.c source code file. A local attacker can mount a malicious ext4 image, trigger NULL pointer dereference in the fs/posix_acl.c:get_acl() function and cause the service to crash.
Affected software
Linux kernel
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power 9
Red Hat Enterprise Linux for IBM System z (Structure A)
kernel-alt (Red Hat package)
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power 9
Red Hat Enterprise Linux for IBM System z (Structure A)
kernel-alt (Red Hat package)
How to mitigate CVE-2018-1095
Install update from vendor's website.
kernel-alt (Red Hat package) - update to 4.14.0-115.el7a