SB2016012024 - Fedora 23 update for kernel

Description

This security bulletin contains information about 3 vulnerabilities.

1) Use-after-free error (CVE-ID: CVE-2016-0728)

CWE-ID: CWE-119 - Memory corruption

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Green

The vulnerability allows a local attacker to gain elevated privileges on the target system.

The weakness exists due to use-after-free error in the join_session_keyring() function in security/keys/process_keys.c when handling keyring object reference counting by Linux kernel's key management subsystem. A local attacker can overflow the usage field via a specially crafted object and execute arbitrary code with root privileges.

Successful exploitation of the vulnerability may result in arbitrary code execution on the vulnerable system.

Note: the vulnerability was being actively exploited.

2) NULL pointer dereference (CVE-ID: CVE-2015-7566)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear

The vulnerability allows a local non-authenticated attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to NULL pointer dereference within the clie_5_attach() function in drivers/usb/serial/visor.c. A local non-authenticated attacker can perform a denial of service (DoS) attack.

3) Division by zero (CVE-ID: CVE-2015-7513)

CWE-ID: CWE-369 - Divide By Zero

CVSSv4: 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/E:U/U:Clear

The vulnerability allows a local user to a crash the entire system.

The vulnerability exists due to a division by zero error within the kvm_vm_ioctl_get_pit(), kvm_vm_ioctl_get_pit2() and kvm_vm_ioctl_set_pit2() functions in arch/x86/kvm/x86.c. A local user can a crash the entire system.

Remediation

Install update from vendor's website.

References

• https://bodhi.fedoraproject.org/updates/FEDORA-2016-b59fd603be