NULL pointer dereference in Linux kernel - CVE-2018-1094
Published: April 4, 2018
Vulnerability identifier: #VU11520
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-2018-1094
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 initialization of the crc32c checksum driver when using the ext4_fill_super function, as defined in the fs/ext4/super.c source code file. A local attacker can mount a customized ext4 image, trigger NULL pointer dereference in the ext4/xattr.c:ext4_xattr_inode_hash() function and cause the service to crash.
The weakness exists due to improper initialization of the crc32c checksum driver when using the ext4_fill_super function, as defined in the fs/ext4/super.c source code file. A local attacker can mount a customized ext4 image, trigger NULL pointer dereference in the ext4/xattr.c:ext4_xattr_inode_hash() 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)
Opensuse
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)
Opensuse
kernel-alt (Red Hat package)
How to mitigate CVE-2018-1094
Install update from vendor's website.
kernel-alt (Red Hat package) - update to 4.14.0-115.el7a